MEMOIRS
California Academy of Sciences
Volume III
MEMOIRS
OF THE
California Academy of Sciences
Volume III
THE PALEONTOLOGY AND STRATIGRAPHY OF THE
MARINE PLIOCENE AND PLEISTOCENE
OF SAN PEDRO, CALIFORNIA
By RALPH ARNOLD
Issued June 27, 1903
SAN FRANCISCO
Published uy the Acade:\iv
1903
'T
^^ 7 /
THE PALEONTOLOGY AND STRATIGRAPHY OF THE MARINE
PLIOCENE AND PLEISTOCENE OF SAN PEDRO,
CALIFORNIA.
BY RALPH ARNOLD.
CONTENTS.
Plates I-XXXVII.
Page
Introduction and Acknowledgments 9
Pabt I. Genekax Discussion.
CHAPTER I. TOPOGRAPHY AND GEOLOGY OF SAN PEDRO 11
1 . Topography 11
2. General Geology 12
3. Pliocene 14
Deadman Island 14
Timings Point 17
4. Pleistocene 17
The San Pedro Series 17
Lower San Pedro Series 18
Upper San Pedro Series 23
Raised Beach Formation 33
5. Post-Pleistocene Deposits 33
6. Alphabetical List showing the DisTRiBnTiON of Specie-s in the vicinity of San Pedro... 34
CHAPTER ir. THE UPPER PLIOCENE AND PLEISTOCENE FORMATIONS OF OTHER LOCALITIES
ON THE PACIFIC COAST 48
PoGET Sound South to Pismo, San Luis Obispo County 48
Santa Barbara and Vicinity South to San Joan Capistrano 50
Ventura 53
Port Los Angeles 56
San Clemenle Island 56
Newport 56
San Juan Capistrano 57
San Diego and Vicinity .'. 57
Pacific Beach — Pliocene 57
Pacific Beach — Pleistocene .' 58
San Dier/o Mesa — Pliocene 59
Twenty-sixth Street — Pleistocene 59
Spanish Biijht —Pleistocene 59
CHAPTER IIL FAUNAE RELATIONS 65
1. Pliocene 65
2. -Pleistocene 66
The Loicer San Pedro Series 66
The Upper San Pedro Series 66
3. Relation of the Late Pliocene, Pleistocene, and Living Faunas of California to the
Fauna of Japan 6¥
(7)
8 CALIFORNIA ACADEMY OF SCIENCES.
Pabt II. The I'liocknk and Pleistocene Fauna of San Pedro and Vicinity.
Synopsis 71
De.scrii'tion of Species 80
Pabt III. Bibliography.
Explanation of Plates 364
Index 405
INTRODUCTION AND ACKNOWLEDGMENTS.
Errata
Page 107, last line, after (Cooper) insert San Pedro; Santa Barbara (Arnold).
Page 112, 17th line, for " Jlucicolus" re&d fucicolus.
Page 142, last line, after Cytherea insert radiata Sby.
Page 144, 4th line from bottom, after Carpenter insert var.
Page 145, 4th line, for "C diaphana" read C. subdiaphana.
Page, 166, i2th line from bottom, after Sowerby insert var.
Page 185, top line u{ foot-note, lor " Dr. W. N. Dall " read Dr. W. H. Dall.
Page 233, nth line from bottom, for ",!/. woodwardi" read N. wood'cvardi, and for " gibbsW" read
gibbesii.
Page 243, 5th line, for " feniuspe7ia'' read tenuispina.
Page 253, 7th line, for " stuarti Smith var." read orpheus var.
Page 307, 17th and 19th lines, for '' Calyptrea" read Calyptrcea.
Page 339, 3rd line, for " Fissuridiz" read Fissuridea.
Besides the collection of Delos Arnold, the writer has had access to tlie
collections or material belonging to the following institutions or individuals:
1. Leland Stanford Junior University: Geological Department collections.
2. University of California: Geological Department collections, State Geo-
logical Survey collections, and State Mining Bureau collections.
3. California Academy of Sciences: Paleontological and Conchological
collections.
4. The private collection of Mrs. M. Burton Williamson, Los Angeles?,
California.
5. The private collection of Mrs. T. S. Oldroyd, Los Angeles, California.
(). The private collection of Mr. Henry Hemphill, San Diego, California.
C 2 I ( 9 J September 22, 1902.
8 CALIFORNIA ACADEMY OF SCIENCES.
Paet II. The Pliocenk and Pi^eistocene Fauna of San Pedro amj Vicinity.
Synopsis '1
Description of Species 86
Pakt III. Bibliography.
INTRODUCTION AND ACKNOWLEDGMENTS.
The field work upon which this paper is based began in the winter of 1886,
when the writer first visited the fossil-bearing beds of San Pedro. Since that time
several visits have been made each year to the beds in that vicinity, generally after
heavy rains, when landslides and the breaking off of the banks have given new
exposures. The specimens obtained during these excursions are in the collection of
the writer's father, Delos Arnold of Pasadena, California, and have furnished most
of the material on which the present paper is based. It was first intended to
compile a list, with synonymy, of the fossils of San Pedro and vicinity, but the scope
of the paper has been enlarged until the present work is the result.
One of the obstacles met with in the preparation of this work has been the
lack of systematic information in regard to the fauna and stratigraphy of the Pleisto-
cene of the Pacific Coast. Dall, Cooper, Gabb, Ashley and Merriam have published
notes on the faunal aspects of the marine Pleistocene of the coast of California; while
Whitney, Lawson, Fairbanks and Ashley have contributed to our knowledge of the
geology and stratigraphy of the Pleistocene. The inadequacy of these observations
has led the writer to visit as many localities as possible in the endeavor to obtain
information that would add to the knowledge of the Pliocene and Pleistocene of
California. Enough evidence was obtained at the different points along the coast to
warrant the statement that we have in the California deposits the greatest develop-
ment of the marine Pleistocene in the world. Future investigations are necessary
in order to give more accurately the thickness of the sediments deposited and
the amount of orogenic movement which has taken place since the beginning of
the Pleistocene epoch. The future study of the Pleistocene fauna will no doubt
add greatly to our knowledge of the relations existing between the Tertiary and
living faunas.
Besides the collection of Delos Arnold, the writer has had access to the
collections or material belonging to the following institutions or individuals:
1. Leland Stanford Junior University: Geological Department collections.
2. University of California: Geological Department collections. State Geo-
logical Survey collections, and State Mining Bureau collections.
3. California Academy of Sciences: Paleontological and Conchological
collections.
4. The private collection of Mrs. M. Burton Williamson, Los Angeles,
California.
5. The private collection of Mrs. T. S. Oldroyd, Los Angeles, California.
6. The private collection of Mr. Henry Hemphill, San Diego, California.
(21 [ 9 ] September 22, 1S02.
10 CALIFORNIA ACADEMY OF HCIENCES.
Dr. James Perrin Smith, Professor of Paleontology in Leland Stanford Junior
Universit}', has had general supervision of this paper during its preparation. He has
accompanied the writer on journeys that covered much of the territory under dis-
cussion, and has offered many valuable suggestions regarding the faunal relations
and stratigraphy of the San Pedro formations.
The writer is indebted to Dr. John C. Branner, Professor of Geology in
Leland Stanford Junior University, for valuable suggestions in regard to the field
work and compilation of this paper.
Dr. William Healey Dall, of the United States National Museum, has
identified numerous specimens sent to him, acknowledgment for which is given
with each species. Dr. Dall has also prepared the diagnoses of the family Pyrami-
dellidse, and has furnished drawings of the species of that family, and for the corals;
and in many otli.er ways has extended courtesies during the preparation of this work.
Dr. John C. Merriam, of the University of California, has given free access to
all of the collections under his charge; has extended many other courtesies; and has
offered suggestions which have added to the value of the paper.
The writer is indebted to his father, Delos Arnold, for the use of his collec-
tion; for notes and suggestions on the stratigraphy of the San Pedro deposits; for
assistance in the prej^aration of the drawings; and, most of all, for the interest mani-
fested by him in procuring the material upon which much of this paper is based.
The field work and collecting has been done as much by him as by the writer. For
the past fifteen years he has made numerous visits each year to the San Pedro beds,
and to his untiring efforts is due the discovery of such a large number of species
in them. He has also visited and made systematic collections from the deposits
of Santa Barbara, Ventura, San Diego and other localities along the southern
California coast.
Acknowledgment is also due to Mr. T. Wayland Vaughan, Dr. R. E. C.
Stearns, Mr. Henry Hemphill, Dr. A. A. Wright, Mr. J. Howard Wilson,
and others.
The illustrations are from drawings by Dr. J. C. McConnell, Misses Winnifred
M. Paine and Fanny H. Mitchell, Messrs. H. R. Johnson, R. E. Renaud and
R. Arnold.
Where the types of new species belonged to Delos Arnold, these types have
been deposited in the United States National Museum at Washington, and, where
possible, duplicates will be dej^osited in the paleontological collections of the California
Academy of Sciences, and of Leland Stanford Junior University.
Pakt I. General Discussiox.
Chapter I.
TOPOGRAPHY AND GEOLOGY OF SAN PEDRO
1. Topography.
The most prominent topographic feature about San Pedro is San Pedro Hill,
an abruptly projecting headland of the coast, rising to a height of 1,482 feet. Along
its southern base is a sea clifi varying in height from one hundred to three hundred
feet, while to the east the cliff rarely exceeds fifty feet in height. The hill is ter-
raced to within two hundred and forty feet of its summit, and the observations here
recorded began on the lowest, or fifty-foot terrace, at the eastern limit of the hill.
(See map, Plate XXIII.)
This terrace extends from a point about one-half mile east of the Point Fer-
min lighthouse to a bluft' about a half mile north of the business center of the town of
San Pedro. The sea cliff bounding this terrace runs due north for nearly a mile and
a half from Point Fermi n, then bends abruptly at old San Pedro, popularly known as
" Crawfish George's," and runs northeastward for half a mile to Timm's Point. From
this point the bluf! runs due north for over a mile, broken only by a little valley in
which the business portion of San Pedro is located. At the north end of this bluff
the escarpment bends sharjily toward the northwest, and is broken along the north-
ern front by several valleys that run down from San Pedro Hill.
Half a mile southeast of Timm's Point is Deadman Island, a small fragment
of the San Pedro terrace, which has withstood the eroding agents that have cut it
off from the mainland, but which is now being worn away rapidly by the waves. It
is a triangular bit of land about fifty feet high, with an area on top of about three
hundred square yards. Deadman Island is joined by a breakwater to Rattlesnake
Island, or Terminal Island, as it is now called, a narrow barrier beach, which begins
at a point directly opposite San Pedro and runs to Old River — the former mouth of
the Los Angeles River — about four miles distant.
About a mile east from Old River a ten-foot bank forms the eastern limit of
the marsh lands and the western edge of a plain that rises toward the east for about
three and a quarter miles, where it is terminated by a bluff. The bluff, which forms
the coast-line of this plain, gradually rises in height from ten feet at its western ex-
tremity to over fifty feet at about its middle. The eastern half is of a nearly uniform
height of fifty feet.
The town of Long Beach is situated on the plain that slopes gradually back
[11]
12 CALIFORNIA ACADEMY OF SCIENCES.
from this bluff. Two and a half miles north of Long Beach is Los Cerritos, or
Signal Hill, as it is commonly called, the most prominent point in a series of low hills
extending to Dominguez Hill, six miles to the northwest. Los Cerritos is three
hundred and sixty-four feet high. Its northern side is smooth and slopes gently into
the great Los Angeles plain. Its southern slope is much steeper, and is cut by many
deep, narrow ravines, which offer a fine opportunity for studying the geology of the hill.
2. General Geology.
The oldest formation exposed in the immediate vicinity of San Pedro is the
Miocene, or Monterey series. The shales of this formation are exposed along the sea
cliff on the eastern end of San Pedro Hill, and also at Deadman Island. After the
deposition of the Miocene the shale beds were raised and contorted and subjected to
erosion. During the Pliocene period a submergence took place and a deposit of fine,
yellow, clayey sand of unknown thickness was laid down on the surface of the eroded
Miocene shales.
A post-Pliocene uplift laid bare the sandstones, which were worn away com-
pletely from some parts of the eastern base of San Pedro Hill. Timra's Point and
Deadman Island are the only places at which they are now exposed.
Again there was a change of conditions. The eroded surface of the Pliocene
became sea bottom, and deposits of fine, gray, silicious sand, extremely fossiliferous
in places, were laid down unconformably on it. This particular horizon is repre-
sented by the gray sand deposit of Deadman Island, by the gray, sandy strata
exposed along the bluff southeast of San Pedro and in the lower part of the continua-
tion of this bluff just north of the San Pedro valley. The lower series of sandstones
and conglomerates of Los Cerritos may be contemporaneous with these last men-
tioned beds. On account of its fauna and its unconformable position on the Pliocene
this horizon is thought to be of Pleistocene age. It is called in this paper the
lower San Pedro series. The maximum thickness of this particular horizon, so far
seen, does not exceed fifty feet.
After the lower San Pedro there was a period of shallow water, lagoon and
dune conditions prevalent along this part of the coast, during which the conglomerates
of Deadman Island, San Pedro and Los Cerritos were laid down, and the sandy forma-
tions in the bluffs one-half mile north of San Pedro and along the Long Beach water
front were dejiosited. This period was one of rapidly changing conditions, as is
shown by sand-dune deposits and by the nearly horizontal aqueous deposits of both
tine sand and gravels in alternating beds. These beds dip gently away from the
centers of uplift, and many of the strata are very fossiliferous. This series of strata
is called the upper San Pedro series. The maximum thickness of the strata of this
horizon is over fifty feet, as is shown by the exposure in the sea-cliff southeast of
Long Beach.
Overlying all these deposits is the alluvial soil, varying in depth from two to
ten feet, mostly adobe, and filled in some places, notably along the San Pedro bluffs
and Deadman Island, with the shells of edible mollusks. These refuse heaps, or
ancient kitchen-middens, are abundant on this part of the coast.
ARNOLD — THE PALEONTOLOGY AND STRATIGEAPHY OF SAN PEDRO .
13
Correlation Table of the Marine Pliocene and Pleistocene of California.
(Dotted lines indicate conformable strata; full lines, nonconformable.)
*id
15
(S
o
a
o
a
a
0
a
oo
o
i-d 2
Pliocene
Pleistocene
Merced Series
Sau Diego Formatiou
Lower . Upper
Lower
San Pedro Series
Upper
San Diego well
150'
Euss
School
50'
Pacific Beach
(lower horizon)
180'+
Pac.
Beach
(Upper
horizou)
20'±
Fool of 26th St.
20'
Spanish Bight
20'
Dead man
Island
45'
BIO
Deadman
Island
12'
Timm's Point
50'
San Pedro
Bluffs
50'
Los Cerritos
50'+
Pacific Beach
15'
Deadman Island
10'
Lumber yard
20'
Crawfish George's
3'
Los Cerritos
20'
Long Beach
50'
Dead.
}uau Is.
4'
Epoch
1^
o
so
>
O "
o
o
*Ti
+
Old irrigating ditch
(?)
Old irrigating ditch
1000'+
Barlow's Ranch
100'+
g B
■= a
O CD
2
■Ro
c
Packard's
Hill
200'+
Bluff at
bath house
30'
Bluff i mile west of
bath house
25'
Bluff 2 miles east of
wharf
30'
>
m >
a
3 W
o >
z w
. a
>
to
>
»ti
oo gg.
+ P +§
td
Lake Merced to Mussel Rock
below "upper gastropod bed."
5000'+
"Upper gas
tropod bed" to
uucouform-
ity. 150'+
"Terrace formation."
Soft sediments above
uucouformitv.
200'+
San Juan
CaiJistrauo
Newpoi't,
Orange County.
Port Los
Angeles, fos-
siliferous bed
50'+
Bell Station,
Los Angeles County
1320'
Port Los Angeles,
upper soft strata
150'+
W
San Pablo Bay,
oyster beds
c >.
!^
CDS
3 ^
o to
o
X
t-l
o
14 califoenia academy of sciences.
3. Pliocene.
Deadman Island. — Overlying the Miocene shale of Deadnian Island (see
diagram B, PI. XXII) is a deposit of brown, clayey sandstone, varying in thick-
ness from twenty to forty-five feet. The distinct .strata of this formation will be
described in detail. The surface of jointed shale on which the sandstone rests is
worn and uneven, but the contact conforms nearly to the dip of the shale, which is
between 20° and 30" northea.st. Other evidence beside the worn condition of the
shales at the contact goes to show that the erosion took place while the shales formed
the sea bottom near the shore. Worm borings are common, and in one place a
pholas hole was found in the shale. The contact stratum, which is only about a foot
thick, is composed almost wholly of beach-worn pebbles of the Miocene shale, all
containing to some extent holes of worms and mollusks. It contains also many well
preserved shells and shell fragments. All of the fossils common in this layer are
found in the sandstone just above it, so its fauna will be taken up with that of the
overlying sandstone in a later part of this paper.
This bottom Pliocene layer dips northeast at an angle of about 25°. Towards
the top of the formation the bedding planes become more nearly horizontal, those at
the top having a dip of only 8° or 10°. This could be accounted for in one of two
ways — either the lowest layer was deposited horizontally and then during the deposi-
tion of the subsequent layers there was a gradual uplift toward the southwest, or else
the lowest layer was deposited on a sloping bottom, and the general tendency of
sediments to settle in the lower portions of their basins and to form horizontal beds
gradually overcame the dip.
About eight feet of fine, brownish yellow, clayey sand rests on the pebbly low-
est Pliocene stratum. In some of the places exposed to the action of the sea-water
this second Pliocene stratum consists of bluish gray clay, and in some places is filled
with well preserved fossils. In the southwest corner of the island the second layer
is a hard, fine, brown sandstone containing only a few fossils.
Overlying the second stratum is a fine, dark brown sandstone about four feet
thick. The most fossiliferous places are hard, but porous. The fossils in these hard
places are well preserved, while those in the softer parts of the layer, which is lighter
colored, are poorly preserved and fragile. Pieces of the hard portions of the Plio-
cene stratum have broken off and have fallen amono; the frascments of shale along the
beach. This has caused some people to report the fossils found in this Pliocene bed
as occurring in the Miocene shale. On account of the great abundance of lliijasira
fOryptodonJ bisecta in this stratum it has been given the local name of "Cryptodon
bed." Lucina acutilineata is also very common in the Cryptodon stratum.
Above this very fossiliferous stratum is a bed of brown sandstone from twenty-
five to thirty-five feet in thickness, only slightly laminated, and varying somewhat in
structure and appearance in different parts of the layer. The lower part is uni-
formly soft, while toward the top the color is lighter and the rock much harder.
Only a few fossils, such as Lucina acutilineata and Pecten caurinus, have been found
in the upper brown sandstone stratum. The total thickness of the Pliocene beds at
Deadman Island is about forty-five feet.
ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO.
15
List of Species Found in the Pliocene of Deadman Island.
(P indicates species living at San Pedro ; N indicates species found living only noi-th of San Pedro;
E indicates extinct species or those not known as living.)
Callhia siihdiaphana, I*
Ghama pclliicida, P
Corhula tiUcola^ P
CumiiKi'm californica, I
Kellia lapcrousii, P
Leda taphria, P
Lucina actitilineala, V
Lucina californicu, P
Ljjonsia caUfornka, P
Macoma inquinala, P
Acmaa insessa, P
Amphissa corriu/ata, P
Bc'la fidicula, N
Bittium anperum, P
Calliostoma ranaliculaium, P
Calliosloma tricolor, P
Cerithidea californica, P
Chlorostoma hruniieiim, P
Chlorosloma moniereyi, P
Chrysodomus sp. indet., N
Chrysodomus reclirostris, N
Chrysodomus tabulalus, P.
Clathurelta conracliana, E
Ooliimbella gausapata, P
Coliimbella var. carincUa, P
Conus cali/ornicus, P
Cryplochilon stelleri, N
DriUia merriami, E
Drillia torosa, P
PELECYPODA.
Mylilimeria nuitalli, P
Nuciila caslrcnsis, P
Panomya ampla, N
Panopea generosa, P
Pecten caurinus, N
Pecten hastatus, P
Pcelen hericeus, N
Pecten jordani, E
Pecten slcarnsii, E
GASTROPODA.
Fusus barharensis, E
Hipponyx antiqualus, P
Littorina planaxis, P
Mangilia sculplurata, P
Na^sa californiuna, P
Nassa fossa la, P
Nassa mendica, P
Nassa var. cooperi, P
Nasscc perpiiiguis, P
Natica clausa, N
Neverita recluziana, P
Ocinebra interfossa, P
Olivella biplicala, P
Olioella intorta, P
Olivella pedroana, P
Pleurotoma bartschi, E
Pleurotoma dalli, E
Pleurotoma perversa, P
Pleurotoma nnaudi, E
P/iolndidea penita, P
Protorardia c.entifilosa, P
Solett sicarius, P
Thracia trapczoides, E
Thyasira bisecta, N
Thyasira gouldii, P
Venericardia barbarensis, P
Venericardia venlricosa, N
FejiMS similtima, P
Pleurotoma smithi, E
Prime oregonensis, P
Puncturella cucullata, N
Puncturtlla galeata, N
Scala indianorum, P
Solariella cidaris, P
Solariella peramabilis, P
Taranus strong!, E
Terehra simplex, P
Thalotia caffea, P
Tornatina eximia, P
Trophon gracilis, P
Tropihon scalariformis, N
Trophon stuarti, N
Trophon var. precursor, ]
Trophon tenuisculpta, E
Turritclla cooperi, P
Turritella jewetti, E
Bryozoan remains,
BRACHIOPODA.
Laqucus jeffreysi, N
Tercbratalia smithi.
Resume.
Total number of species 87
Pelecypoda, species 28
Gastropoda, species 56
Brachiopoda, species 2
Biyozoa, species ?
Species now living at San Pedro 55
Percentage of the whole fauna 63.1
Species living only north of San Pedro 16
Percentage of the whole fauna 18.5
Species living only south of San Pedro 0
Percentage of the whole fauna 0
Species extinct or not known as living 15
Percentage of the whole fauna 17.3
Species of questionable habitat 1
Percentage of the whole fauna 1.2
16 (JALIFOKNIA ACADEMY OF SCIENCES.
The fauna of the San Pedro Pliocene is a decidedly northern or boreal one
in the sense that many of the species found in the San Pedro Pliocene are living now
only in the colder waters far to the north of San Pedro. The large percentage of the
living species found now living only north of San Pedro shows this; and in addition,
the species in this fauna still living at San Pedro are neai'ly all of a northern
or boreal type. No characteristic southern species are found in this fauna.
The evidence shows that the climate in the vicinity of San Pedro during that
part of the Pliocene epoch in which these beds were deposited was probably
different from the present one. A boreal fauna deposited in comparatively shallow
water near the shore implies a boreal climate, at least in proximity to the coast;
the fauna contains so many shallow water species, and the lithologic evidence showing
that the deposits containing the fauna were laid down near the shore is so strong, that
it cannot be regarded as a deep-water temperate fauna. The evidence, then, shows
that during upper Pliocene times the climate of this part of Southern California was
colder than at present; and if this was true of southern California, it seems reasonable
to infer that the colder climate affected the whole coast from San Pedro northward.
There are several reasons for calling the lower sandstone strata of Deadman
Island Pliocene. In the first place, 17.3 per cent, of the fauna of these strata are
extinct at the present time. This is conclusive evidence that the beds are not
Pleistocene, but are of an earlier epoch. They are overlain unconforraably by
strata of Pleistocene age, which implies that there was a period of denudation
between the epoch of the deposition of the lower beds and the Pleistocene. Besides,
these strata rest unconformably upon the Miocene shales. That the Deadman Island
Pliocene beds are of upper Pliocene origin is shown by the fact that their fauna
gradually grades into the living fauna of San Pedro through that of the overlying
Pleistocene beds. The gap between the faunas of the Deadman Island Pliocene and
the overlying Pleistocene beds, though distinct, is not wide.
In his correlation paper on the Neocene, Dr. Dall says:' "It appears that on
Deadman Island near Point Fermin at least three distinguishable strata appear, the
uppermost of which is certainly Pleistocene, while the others are Neocene and the
middle layer probably Pliocene." The middle layer referred to is the brown sand-
stone which rests on the Miocene shales.
The Deadman Island Pliocene beds are lithologically and faunally similar to
the Pliocene beds at San Diego, and have been correlated with them by Dr. Dall.^
In the same table he places the San Diego beds below the Merced series. This does
not accord with the evidence offered by the San Pedro Pliocene strata. The San
Pedro beds are very near the top of the Pliocene, and have a northern fauna; the
relative position of the Merced series is uncertain, and it has a fauna containing such
southern forms as Area and Dosinia, with an echinoderm, Scntella interlineata, which
has never been found in either the San Diego or San Pedro formations, or in any
formation overlying the Merced series. The Merced series has been subject to
> Correlation Papers, Neocene. By W. H. Dall and G. D. HarriB. Bull. U. 8. Geol. Sur., No. 81, 1892, p. 216.
-' North Aujerican Tertiary Horizons. By W. H. Dall. 18tb Ann. Eep. U. 8. Geol. Sur., Part II, 1898, p. 336.
ARNOLD— THE PALEONTOLOGY AND STRATlGEAPHY OF SAN PEDRO. 17
much more contortion than either the Deadman Island or San Diego Pliocene.
The Pliocene age of the Merced series is unquestioned, and it has too great a
vertical development to allow of its coming between the Pleistocene and the Dead-
man Island formation, which is at or near the top of the Pliocene. In the light of
this evidence, it is the writer's opinion that the Deadman Island and San Diego
Pliocene are above the greater irAvt of the Merced series.
2'imm's Puint. — The Pliocene is also exposed at Timm's Point (see diagram
D, pi. XXII), where it is similar in every respect to the Deadman Island Plio-
cene, except that the layers are not so distinctly separated as at Deadman Island,
and, as a whole, the rocks are not so hard as at the latter place. The Miocene shales
at Timm's Point dip northeast at an angle of about 25°; and resting on them in the
same relative position as at Deadman Island, is the Pliocene sandstone. The
Pliocene is also visible in the railroad cut in the bluflf in the southeastern part of San
Pedro, where there is a stratum containing numerous specimens of Thracia trapezoidea.
The beds along this cut dip gently in a northerly direction, and are ovei'lain in the
cut and to the north of it by the lighter colored Pleistocene sands.
The following species were found in the Pliocene deposits at Timm's Point
and in the northward continuation of the same strata in the railroad cut and grade:
List of Species Found in the Pliocene at Timm's Point.
pelecypoda.
Callista subdiaphana Pecteii jordani Thracia trapezoides
Leda taphria Protocardia cenlifilosa Thyasira gouldii
Lucina acutilineala Solen sicarius Venericardia hurbarensis
Nucula castrensis I'hyasira bisecla Venericardia ventricosa
Pectcn caurinus
GASTROPODA.
Biltium asperum DriUia torosa Natica clausa
Chrysodomus tabulatus Fusus barbarensis Olivella biplicata
Columbella rjausapata Nassa mendica Terebra simplex
Columbella var. carinala N^assa cooperi Trophon sluarli
Conus californicus Nassa perpinguis Turriiella cooperi
This fauna contains a total of twenty-eight species, of which thirteen are
pelecypods and fifteen are gastropods. The fauna, so far as known, is small, not
because the beds at that place are barren of fossils, but because little collecting
has been done there. The beds are nearly covered with detritus, so that fossils are
not easily obtained.
An outcrop of rather hard, fine grained sandstone on the coast about three
and one-half miles east of Long Beach has some of the lithologic characters of the
Deadman Island Pliocene beds. Although a few fragments of shells were seen in it,
no recognizable fossils were obtained from this outcrop, and no definite correlation
will therefore be attempted. It may be only a local hardening of the upper San
Pedro strata.
4. Pleistocene.
llie Snn Pedro Series. — From the evidence brought forward in this paper it
appears probable that most of the Pleistocene, as developed on the coast of California,
( 31 September 23, l'J02.
18
CALIFORNIA ACADEMY OF SCIENCES.
is represented by the strata of San Pedro and Deadman Island. The writer, there-
fore, proposes the name San Pedro Series for the series of Pleistocene strata at San
Pedro, including the lower and upper formations, as described in the present paper.
Lower San Pedro Series. — A stratum of gray sandstone rests unconformably on
the brown Pliocene sandstone of Deadman Island. (See diagram B, PI. XXII.)
In some places the sand is soft; in others it has been cemented until it is very hard.
The soft parts are not fossiliferous, as a rule, while the hard parts are made up in
some places almost wholly of beautifully preserved fossils. One locality in particular
on the west side of the island, near the north end, is filled with finely preserved
specimens. Parts of this bed are very hard, making it almost impossible to get the
shells out, while other parts are so soft that the shells can be removed from the
matrix with the fingers. This stratum varies in thickness from four to ten feet on
the west side to nearly twenty feet on the east side of the island. There seems to be
little indication of bedding planes in this stratum. The general dip is to the north.
On account of its lying unconformably on the Pliocene, being of different lithological
composition, and containing a fauna of which a great number of species have never
been found in the Pliocene, this horizon is designated in the present paper as the
lower San Pedro series, or the lower part of the Pleistocene. The following species
have been obtained from the lower San Pedro gray sand stratum of Deadman Island:
List of the Fossils of the Lower San Pedro Beds (Lower Pleistocene) of
Deadman Island.
(P indicates species living at San Pedro; N indicates species living only north of San Pedro; S indi-
cates species living only south of San Pedro; E indicates extinct species or those not known as living.)
Anffulus buttoni, P
Anomia lampe, P
Bornia relifcra, N
Callisla var. pedroana, E
Cardium cordis, N
Cardi'im procerum, S
Chama pellucida, P
Clidiophora punclala, P
C'ooperella subdiaphana, V
C'orbula luteola, P
Cryjjlomya californica, P
Ciiminyia californica, P
Diplodonta orbclla, P
Donax californica, P
Donax Ufvigata, P
Kellia laperousii, P
KMia siiborbicularis, P
Kennc.rlia bicarinata, N
Kennirliajilosa, N
Laivicardium subslriatum, ]
Lazaria suhipiadrata, P
Ledafonsa, N
Leda hamata, P
Leda var. prcecnrxor, N
Leda taphria, P
PELECYPODA.
Lima dehiscens, P
Lucina aculilincala, P
Lucina californica, P
Lucina nutlalli, P
l^yonsia californica, P
Macoma calcarea, N
Macoma inquinata, P
Macoma nasuta, P
Macoma secla, P
Macoma yoldiformis, ]
Mactra falcata, P
Metis alia, P
Modiola fornicata, N
Modiola recta, P
Moerella salmonea, N
Mi/tilus edulis, P
Mi/lilimeria nutlalli, Ir
Neiera pectinata, P
Nucida caatrensis, P
Nucula suprastriata, I
Oslrea lurida, P
Panopca generosa, P
Pecten caurinus, N
Peclen haslatus, P
Pecten hcriceus, N
Pecten var. strategus, N
Pecten jordani, E
Pecten latiauritus, P
Pecten var. monotimeris, I
Petricola carditoides, P
Petricola denticulata, S
Protocardia centifilosa, P
Psephis salmonea, N
Pscphis tanlilla, N
Racta midulata, P
Saxidomus aratns, P
Semele var. montereiji, N
Septifer hifurcatus, P
Siliqua lucida, P
Solen rosaccus, P
Solen sicarius, P
Tapes siaminea, P
Tellina bodegensis, P
Tivela crassatelloides, P
Venericardia barbarensis,
Venericardia vcntricosa, J>
Ve7ms simillima, P
Verticordia novemcoslata,
Yoldia scissrtrala, P
ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO.
19
Acmoia insessa, P
Acmcea pella, P
Acmaa spectrum, P
Acti^on punctocrelata, P
Admeti' gracilior, E
Amphissa corrugata, P
Amphissa venlricosa, E
Amphissa versicolor, P
Bela_/!dicitla, N
Bela sanctae-monicce, E
Biltium asperum, P
Bittium caU/ortiician, E
Biltium filosum, N
Bittium quadrijilatum, P
Bittium rugatum, P
Ccecum californicum, P
Ccecum crehricinctum, P
Ccecum m.agnum, ?
Calliostoma canaliculatum, P
Calliostoma costatum, P
Cerithidea californica, P
Chlorostoma funebrale , P
Chlorostoma var. subapertum P
Chlorostoma montereyi, P
Chlorostoma var. ligulatum, P
Chrysodomus rcctirostris, N
Chrysodornus tahulatus, P
Clathurella conradiana, E
Clipidella bimaculata, N
Clipidella callomarginata, P
Columbella cali/ortiiana, P
Columbella chrysalloidea, P
Columbella gausapata, P
Columbella var. carinata, P
Columbella oldroydi, E
Columbella tuberosa, P
Conus cali/ornicus, P
Crepidula aculeata, P
Crepidula adunca, P
Crepidula dorsata, P
Crepidula navicelloides, P
Crepidula onyx, S
Crepidula rugosa, P
Cryptochiton stelleri, N
Cylichna alba, P
Cythara branwri, E
Diastoma, sp. indet., ?
Drillia cancellata, N
Drillia hemphilli, S
Drillia inermis, P
Drillia m.crriami, E
Drillia montereyensis, N
Drillia var. penicillata, P
Drillia torosa, P
Eulima falcata, S
Cadulus nitentior, ?
GASTROPODA.
Eulima hantata, S
Eulima micatis, P
Eupleura muriciformis, S
Fissuridea aspera, P
Fissuridea murina, P
Fissurella volcano, P
Fusus barbarensis, E
Fusus luteopicius, P
Fusus robustus, P
Fiisus riigosus, P
Galerus mammillaris, P
Hipponyx antiqualus, P
Hipponyx cranioides, N
Hipponyx lumens, P
Isapis fenestrata, P
Ivara terricula, ?
Lacuna compacta, N
Lacuna porrecla, N
Lacuna solidula, P
Lamellaria stearnsii, P
Leptothyra bactila, P
Leptolhyra carpenter), P
Leptothyra paucicostata, N
Littorina planaxis, P
Littorina scutulata, P
Mangilia angulata, N
Mangilia var. pedroana, E
Mangilia interlirala, P
Mangilia oldroydi, E
Mangilia painei, E
Margarita var. nodosus, P
Margarita var. pedroana, P
Marginella jewetti, P
Melampus olivaccus, P
Mitramorpha Jilosa, P
Mitramorpha intermedia, E
Monoceros engonatum, P
Murex festivus, P
Nassa californiana, P
Nassafossata, P
iVassa mendica, P
Nassa var. cooperi, P
Nassa perpinguis, P
Nassa tegula, P
Natica clausa, N
Neverita recluziana, P
Ocinebra barbarensis, P
Ocinebra interfossa, P
Ocinebra var. aspera, N
Ocinebra var. cerritensis, E
Ocinebra var. munda, N
Ocinebra perita, P
Ocinebra ponlsoni, P
Odoslomia gouldii, P
Odostomia var. avellana, N
SCAPHOPODA.
Dentalium hexagonum, P
Dentalium indianorum, N
Olivella biplicata, P
Olivella intorla, P
Olivella pedroana, P
Phasianella compta, P
Pleurotoma barlschi, E
Pleurotoma dalli, E
Pleurotoma hoovtri, E
Pleurotoma pedroana, E
Pleurotoma perversa, P
Pleurotoma renaudi, E
Pleurotoma smithi, E
Priene oregonensis, P
Puncturella cucullcita, N
Puncturclla galeata, N
Scala hindsii, P
Scala indianorum, P
Scala tincta, P
.9ei7a assimilata, P
Serpulorbis squatnigerus, P
Styliferina tenuisculpta, ?
Taranis strongi, E
Terebra simplex, P
Thalotia caffea, P
Tornatina cerealis, P
Tornatina culcitella, P
Triforis adversa, N
Tropihon cerritensis, E
Trophon gracilis, P
Trophon multicostatus, N
Trophon pedroana, E
Trophon scalari/ormis, N
Trophon stuarti, N
Trophon var. prcecursor, E
Trophon triangulatus, P
Turbonilla adleri, E
Turbonilla arnoldi, E
Turbonilla aurantia, P
Turbonilla crebrijilata, P
Turbonilla gibbosa, P
Turbonilla laminata, P
Turbonilla lowei, E
Turbonilla muricata, P
Turbonilla pentalopha, P
Turbonilla similis, P
Turbonilla subcuspidata, S
7\irbonilla tmuicula, P
Turbonilla torquala, N
Turbonilla var. stylina, N
Turbonilla tridenta, N
Tnrritella cooperi, P
Turritella jewetti, E
Vermicularia, sp. indet., ?
Vitrinella ivilliamsoni, P
Volvarina varia, P
Volvula cylindrica, P
Dentalium pseudohrxagonum.
20 CALIFORNIA ACADEMY OF SCIENCES.
ECHINOIDEA.
Echhiararhniux excentricus, P Strongylocenirotusfraiici/icannx,!' Stronrn/hcenlroluspurpiiratug, P
CKUSTACEA.
Cancer breweri, E
Besum^.
Total number of species 247
Pelecj'poda, species 74
Gastropoda, species 165
Scaphopoda, species 4
Echinoidea, species 3
Crustacea, species 1
Species living at San Pedro 158
Percentage of fauna 64
Species living only north of San Pedro 43
Percentage of fauna 17.4
Specimens living only south of San Pedro 8
Percentage of faima 3.2
Species extinct 31
Percentage of fauna 12.5
Species of questionable habitat 7
Percentage of fauna 3
This is also a cold water fauna. Not only is there a large percentage of
species which are found living only north of San Pedro at the present time, but of
those species in the fauna which are now living at San Pedro, a great manv are
northern forms. A few distinctly southern forms are found in the fauna, however,
which shows that the cold climatic conditions prevalent along this part of the coast
during the upper Pliocene times were beginning to give place to more temperate con-
ditions in the eai'ly part of the Pleistocene. The fauna of the lower San Pedro series
is a transitional one between the boreal fauna of the Pliocene and the warm water
fauna of the upper San Pedro series. The climatic conditions were therefore chang-
ing during lower Pleistocene times; and the climate at the end of the period of de-
position of the lower San Pedro deposits was much warmer than that at the end of the
period of deposition of the Pliocene. The period of denudation between the Pliocene
and Pleistocene epochs was one during which the conditions were also changing.
The lower San Pedro deposits are thought by the writer to be.of Pleistocene
origin, for several reasons. First, we have a fauna with a low percentage of extinct
species. (The high percentage of the list given above is due to the large number of
new species and varieties, many of whicli are close to living forms and are probably
living, but which have not been reported.) The large number of species found in this
fauna which have never been found in beds of known Pliocene origin, and the lack
of several of the typical Pliocene species from its fauna, offer two of the strongest
arguments in favor of the Pleistocene age of the lower San Pedro series. The state
of preservation of the fossils is also an item in favor of their comparatively recent de-
position. It is worthy of note that in several cases the original coloration of the shells
of lower San Pedro fossils is still preserved. The sands, too, of this formation are
always much less oxidized than those of the underlying Pliocene. An unconformity
between this formation and the Pliocene also suggests a lapse of time between
the two.
AKNOLD— THE PALEONTOLOGY AND STEATIGEAPHY OF SAN PEDKO.
21
Dr. Lawson in discussing the movements that have taken place during late
Tertiary and Pleistocene times in the vicinity of San Pedro, says :' "It follows that,
while there is a very profound physical break between the Miocene and Pliocene,
the marine Pliocene and Pleistocene formations are intimately associated, with no
epoch of subaerial denudation between them." The observations of the writer also
show this to be true, although in some places there is evidence of local denudation
between the Pliocene and Pleistocene. At Deadraan Island, in particular, there is
evidence of a period of denudation between the two.
Beds of a fine gray sand, with gentle north dip, rest upon the Pliocene ex-
posed along the railroad grade leading up to the cut in the bluff in the southeastern
portion of San Pedro. (See diagram D, PI. XXII.) The exact relation between
these gray sands and the underlying Pliocene is uncertain, as detritus covers the con-
tact along the face of the bluff. But the gray sand beds seem to rest almost conform-
ably on the yellow Pliocene deposits, both having a low dip toward the north. One
of the layers of gray sand near the top of the bluff north of the railroad grade con-
tains a fauna similar to that of the lower San Pedro stratum of Deadman Island.
This stratum is exposed in the bluff to the north of the San Pedro valley, and also in
two small cuts in the bluff west of the business portion of the town. These gray
sand strata were continuous at one time, the San Pedro valley, which cuts them,
having been formed by recent erosion.
In the bluff to the north of the valley the fossiliferous lower San Pedro stratum
is about forty feet above tide level and dips northward, disappearing under detritus
at the mouth of a small ravine about three hundred yards from the southern end of
the bluff, but aj^pearing again north of the ravine at the base of the bluff. Under-
lying this lower San Pedro bed are gray sandy strata which correspond to the lower
part of this same formation soutii of the valley, and which are unfossiliferous, except
in a few places. The following fossils have been found in the lower San Pedro beds
in the San Pedro bluffs.
List of Fossils of the Lower San Pedro Beds at the San Pedro Bluffs.
Angulus buttoni
Anomia lampe
Cardium corbis
Corbula luteola
Cryptomya calij'oi-nka
Cumingia caUfornica
Donax caUfornica
Donax Icevigala
Hinnites giganteus
Kellia laperousii
Kellia suborbicularls
Lievicardium substriatum
Lazaria subquadrata
PELECYPODA.
Leda var. prcecursor
Leda laphria
Lucina acutiUneata
Lucina caUfornica
Lucina nutlaUi
Lyonsia caUfornica
Macoma nasuia
Macoma secta
Macoma yoldiformis
Maclra falcata
MyliUmcria nuttalli
N^ucula castrensis
Nucula suprastriata
Oslrea lurida
Pecten latiauritus
Peclen \av. monotimerv
Psephis salmonea
Psi'phis iantilla
Scmele decina
Siliqua lucida
Solen rosaceus
Solen sicarius
Tapes staminea
TelUna bodegensis
1 Poat-Pliocene Diastrophism of the Coast of Southern California. By A. C. Lawson. Bull. Dept. Geol., Univ. of California
Vol. 1, 1893, p. 128.
22
CALIFOENIA ACADEMY OF SCIENCES.
Acmtfa insessa
AcUton piinctocielata
Bittium Jilosum
Biitium quadrijilatum
BiUiwm rugatiim
Oacum ralifornirum
(.'cecum crehricinclum
Cacum magnum.
Calliostoma canaliculalum
Calliostoma costatum
Caltiostonia tricolor
Cerilhidra californka
Chlorostoma futiebrale
Chlorostoma var. suhapertum
Chlorostoma var. ligulatum
ChryKodomus labulalus
(-'lalhurella conradiana
Clipidella himaculata
Clipidella callomarginata
Columbella californiana
Columbella chrysalloidea
Columbella gausapata
Columbella var. rarlnaia
Columbella tiiberosa
Conus cali/ornicus
Crepidula aculeata
Crepidula adunca
Crepidula navicelloides
Crepidula onyx
Crucibulum spinosum
Drillia hemphilll
Drillia var. penicillata
Drillia torosa
GASTROPODA.
Eulima micans
Fissuridea aspera
Fissurella volcano
Galerus mammillaris
Hipponyx cranioides
Hipponyx iumciis
Isapis fenestrata
Lacuna porrecla
Leptothyra carpenteri
Liltorina planaxis
Liitorina scutulata
Mangilia angulata
Margarita var. knechti
Margarita var. nodosus
Margarita var. pedroana
Marginella jewctti
Melampus olivaceus
Mitra maura
Monoccros engonatum
Nassa fossata
Nassa m,endica
Nassa var. cooperi
Nassa perpinguis
Nassa tegula
Neveriia recluziana
Ocinebra barbarensis
Ocintbra inter/ossa
Ocinebra var. aspera
Ocinebra var. cerritensis
Ocinebra poulsoni
Odostomia gouldii
Odostomia tenuis
Olivclla biplicata
Olivetla intorta
Olivella pedroana
Pachypoma inaijuale
Paludestrina curta
Paludestrina stolcesi
Phasianella compta
Physa heteroslropha
Planorhis tiimidus
Planorbis vermicularis
Pleuroloma perversa
Scala crebricostata
Scala hindsii
Scala indianorum
Scala tincta
Srrpulorbis sijuamigerus
Taranis slrongi
Tercbra simplex
Tornatina cerealis
Tornatina culcitella
Trophon pedroana
TurboniUa aurantia
Turbonilla crebrifilala
TurboniUa laminata
Turbonilla lowei
Turbonilla muricata
Turbonilla similis
Turbonilla stearnsii
Turbonilla subcuspidata
Turbonilla lenuicula
Turbonilla var. stylina
Turbonilla tridenta
Turrilella cooperi
Volvarina varia
SCAPHOPODA.
Dinlalinm hexagonum Dentalium indianorum
CRUSTACEA.
Balanus concavus
ECHINOIDEA.
Echinarachnius excentricus
This fauna comprises one hundred and forty species, of which thirty-seven are
pelecypods, ninety-nine are gastropods, two are scaphopods, one is a crustacean, and
one an echinoderm. The fauna of the lower beds of the San Pedro bhiflfs approaches
a little nearer that of the upper San Pedro series than does the fauna of the same
formation on Dead man Island. This may mean that part of the lower San Pedro
beds was removed from the Deadman Island deposit before the deposition of the
upper Pleistocene strata.
The following species occur in the lower San Pedro deposits of the San Pedro
bluflfs which have not been reported from the same horizon of Deadman Island:
AKNOLD — THE PALEONTOLOGY AND STKATIGKAPHY OF SAN PEDKO.
23
List of Fossils fkom the Lower San Pedro Beds of the San Pedro Bluffs not
FOUND at DeADMAN IsLAND.
(P indicates species living at San Pedro ; N indicates species living only north of Sau Pedro ; S indicates species
living only south of Sau Pedro ; E indicates extinct species, or species not known as living.
Calliostoma tricolor, P
Crucibulum spinosum, I
Margarita var. knechti,
Odostomia tenuis, P
PELECYPODA.
Hinniles giijanleus, P
GASTROPODA.
Pachypoma inaquale, P
Paludi strina citrta, E
Paludestrina stokesi, E
Physa heterostropha, P
Semele dccisa, P
Planorbis tumidus, S
Planorbis vermicularis,
Scala crebricostata, P
Turbonilla stearnsii, S
Upper San Pedro Series. — Kesting on tlie gray sandstone of the lower San
Pedro series at Deadraan Island is a stratum of fossiliferous gravel hardened by calca-
reous cement. (See Diagram B, PI. XXII.) This stratum, which extends over the
whole island at about six feet below the surface, is from two to three feet in thickness.
The matrix varies from fine sand to water-worn pebbles of Miocene shale, many of
which are full of pholas holes still containing the shell. The fossils are well pre-
served, and, in all but a few localities of exceptional hardness, may be removed from
the matrix witli the fingers. This stratum lies nearly horizontal. Water-worn boulders
of the gray lower San Pedro sandstone occur in the upper San Pedro conglomerate at
Deadman Island. This evidence indicates an unconformity between the lower and
upper San Pedro series. Similar evidence is noticeable in the bluff north of the San
Pedro vallev.
List of Fossils from the Upper San Pedro Gravel Stratum, Deadman Island.
Angulus buttoni
Cardium corbis
Chama pellucida
Cryplomya californica
Cumingia californica
Donax Icevigata
Glycymeris barbarensis
Glycymeris septnitrionalis
Hinnites giganteus
LcEvicardium substrialtini
Leda taphria
Lucina acutilineata
Lucina californica
Lucina nuttalli
Lyonsia californica
Macoma inquinata
AcmcBa inscsna
Acmoia spectrum
Amphissa versicolor
Bitlium quadrif latum
Bittium rugatum
Bulla punctulata
PELECYPODA.
Macoma nasuta
Macoma secta
Mactra catilliformis
Mactra falcata
Metis alia
Modiola recta
Mytilus cdulis
Panopea gcnerosa
Pecten latiauritus
Pecten var. monotlmeris
Pecten subnodosus
Pecten ventricosus
Periploma argentaria
Petricola carditoides
Pholadidea penita
Plalyodon cancellalus
GASTROPODA.
Calliostoma canaliculatum
Cerithidca californica
Chlorostoma brunneum
Chlorostoma funebrale
Chlorostoma var. subaperlnm
Chlorostoma gallina
Pododesmus macroschisma
Psephis tantilla
Pu2)ellaria lamellifera
Saxidomus aratus
Semele decisa
Solen rosaceus
Solen sicarius
Tagelus californianus
Tapes staminea
Tapes tcnerrima
Tellina bodegensis
Tivela crassatelloides
Tre.sus nuttalli
Venus simillima
Venus succincta
Zirphma gabbi
Chlorostoma montereyi
Chlorostoma var. ligulalum
Columbclla ga usapata
Columbella var. carinata
Columhella tuberosa
Conus californicus
24
CALIFORNIA ACADEMY OF SCIENCES.
Crepidula adunca
Crepidula grandis
Crepidula navicelloidtx
Crepidula onyx
Crepidula riujosa
Crucibulum spinosum
Cypreea spadicea
Drillia var. penicillala
Driliia iorosa
Eupleura muriciformis
Fissuridea aspera
Fissuridea incequalis
Fissuridea niurina
Fissurella volcano
Fusus barbarensis
Fhtsus lutcopiclus
Fusus robustus
Haliolis fulrje.ns
Hipponyx cranioides
Hiyiponyx lumens
Isapis fencstrata
Lacuna porrecla
Ocinebra poulsoni
Olivella biplicala
Olivclla intorta
Olivella pedroana
Pisania fortis
Pleurotoma carpenteriana
Pleurotoma perversa
Priene oregonensis
Purpura crispata
Ranella californica
Hcala crebricostata
Scala hindsii
Scala indianorum
Scala lincla
Serpulorbis squamigerus
Spiroglyphus liluella
Terebra simplex
Tornalina culcitclla
Turrilella cooperi
Turrilella jeivetli
Volvnrinn varin
Litlorina scutulata
Margarita var. pedroana
Marginella jewelti
Melampus oiivaceus
Mitra maura
Monoceros engonaium
Murex feslivus
Murex trialatus
Nassa californiana
Nassa fossata
Nassa mendica
Nassa var. cooperi
Nassa perpinguis
Nassa tegula
Natica leimsii
Neverila recluziana
Norrisia norrisii
Ocinebra interfossa
Ocinebra Iceepi
Ocinebra var. aspera
Ocinebra perita
CEUSTACEA.
Balanus concavus
ECHINOIDEA.
Echinarachnius exeentricus
SCAPHOPODA.
Dentaliuin semipolituin. Denialium hexagonum
This fauna comprises one hundred and thirty-four species, of which forty-
eight are pelecypods, eighty-two are gastropods, two are scaphopods, one is a crusta-
cean, and one is an echinoderm. This fauna is not as large as that of the upper
San Pedro series at the north end of the San Pedro bhiff, so the discussion of the
faana will follow the list of species obtained from the latter locality.
There is a railroad cut a few feet in depth near the southwestern limit of the
San Pedro terrace. (See I), diagram U, PI. XXIII.) On both sides of this cut
there is exposed a bed of gravel consisting of sand, numerous well preserved fossils,
and water-worn pebbles of Miocene shale, many of which are full of pholas holes.
The bed is from two to three feet thick, and rests unconformably on the upturned
edges of the Miocene shale, which at this point dips northeast at an angle of about
15°. The gravel stratum dips gently toward the south, and is overlain by soil, which
varies from three to five feet in thickiiess, growing thicker toward the south. This
layer is also exposed at the top of the sea-cliff near D, and at many places along the
top of the cliff from D to Timm's Point. This formation is exceptionally well de-
veloped on the sides of the ravine which cuts the bluff at Crawfish George's, showing
a thickness of three feet, very fossiliferous, and, in some places, hardened by calcare-
ous cement. The deposit at Crawfish George's is mentioned by Ashley,^ who refers
it to the Pliocene.
1 Neoceue of the Santa Oniz Mountains. By Geo. H. Ashley. Proc. Cal, Acad. Sci., 2nd Ser., Vol. V, 1894, p. 341.
ARNOLD — THE PALEONTOLOGY AND STKATIGKAPHY OF SAN PEDKO.
25
List of Fossils Collected at Crawfish George's.
Angulus biMoni
Anomia lainpc
Oardium corbis
Chania pelluckla
Cryptomya cali/oniiea
Cum'mgia californica
Diplodonta orbe.lla
Donax Icevigala
Glycymeris barbarensis
Glycymeris seplenirionalis
Lcevicardhtm siibstrialum
Lazaria subquadrata
Leda taphria
Lucina acuiilinenfa
Lucina cali/oniica
Lucina nullaUi
Acmcea depicta
Acmcea hisnssa
Acm(Ba histabilis
Acmcea mitra
Acmcea paUacea
Amphissa corrui/atn
Amphlssa versicolor
Bela fidicula
Bittiuni aspe.rum
Bittium filosum
Billium quadrifilalum
Bittium rucjatnm
Bulla punctidcUa
Ccecum crebricinctum
Oalliostoma canaliculalum
Calliostoma costatum
Calliostoma gcmmulalum
Calliostoma tricolor
Certhidea californica
Ghlorostomci hrunneum
Chloroslomci funebrale
Chlorostoma var. subaprrtum
Chlorosioma cjallina
Chlorostoma montereyi
Chlorostoma ligulatum
Chorus belcheri
Chrysodomus rcctirostris
Glijuidella callomarginata
Columbrlla gausapata
Columbella var. carinata
Columbella tuhcrosa
Conus californicus
Denlalium semipolitum
(4)
PELECYPODA.
Lyonsia californica
Macomti iiiijuinata
Macomn nctsula
Macoma secla
Macira catilliformis
Maclra falcata
Metis alt a
Mytilus edulis
Oslrea lurida
Pecten caurinus
Peclen hastatus
Pecten latiaurittts
Peclen var. monotimeris
Pecten venlricosus
Periploma argentarici
Pctricola cardiloides
GASTROPODA.
Crepidtcla dorsata
Crepidtila navicelloides
Crepidula rugosa
Crucibidum spinosum
Drillia var. penicillata
Drillia torosa
Eulima micans
Fissuridea aspern
Fissuridea murina
Fissurella volcano
Fusus barbarensis
Fusus luteojnctus
Fusus rohtstus
Oalerus mammillaris
Isapis feneslrata
Lacuna porrecta
Leptothyra carpenteri
Litlorina scutulata
Mangilia angulata
Mangilia var. pedroana
Marginclla jcwetti
Melampus olivaceus
Mitra maura
Monoceros engonatmn
Murex festivus
Murex leeanus
Murex trialatus
Nassa cerritensis
Nassa fossala
Nassa mendica
Nassa var. cooperi
Nassa pcrpincjuis
CRUSTACEA.
Balanus concavus
ECHINOIDEA.
Echiixarachnius excenlricus
SCAPHOPODA.
Dentalium indianorum
Pholadidea penita
Plntyodon cancellntus
Pododesmus macroschisma
Saxidomus aratus
Solen rosacevs
Solen sicarius
Tagelus californianus
Tapes staminea
Tapes tenerrima
Teliina bodegensis
Tivela crassalelloides
Tresus nuttalli
Venericardia barbarensis
Venus simillima
Venus succincla
Zirphaea gabbi
Nassa tegula
Naiica lewisii
Neverita recluziana
Ocinebra interfossa
Ocinebra lurida
Ocinebra var. aspera
Ocinebra var. cerritensis
Ocinebra micheli
Ocinebra perita
Ocinebra poulsoni
Olivella biplicata
Olivella intoria
Olivella pedroana
Pachypoma incequale
Phorcus pulligo
Pleurotoma carpenteriana
Pomaulax undosus
Priene oregone.nsis
Purpura crispaia
Ranelta californica
Scata indianorum
Scala tincta
Serpulorbis sqiiatyiigerus
Spiroglyphus lituella
Sijihonalia kellcltii
Terebra simplex
Tornalina culcitella
Trophon pedroana
Trophon scalariformis
Turritclla cooperi
Turritella jewetti
Voivarina varia
Dentalium hexagonuni
September 24, 1902.
26 CALIFOKNIA ACADEMY OF SCIENCES.
The fauna of Crawfish George's consists of one hundred and fifty-three
species, of which forty-eight are pelecypods, one hundred are gastropods, three are
scaphopods, one is an echinoderm, and one is a crustacean. It is similar to the
upper fauna of the San Pedro bluff, with the exception that it affords a few s^iecies
common in the lower San Pedro series that are not found in the upper beds at any
other locality. Another noticeable fact is the great preponderance in numbers of
gastropods over pelecypods. The fauna seems to be that of a rocky beach.
All along the cliff, from Crawfish George's to Timm's Point, the gravel lies
unconformably in disconnected masses on the Miocene shale, and is covered by soil
varying in depth from three to ten feet. From Timm's Point to the north along the
bluff this formation is not exposed until a point is reached a little north of the rail-
way cut. Here the typical gravel of the upper San Pedro series rests unconformably
upon the lower San Pedro gray sand, and is overlain by a layer of soil. The
upper San Pedro gravel (see diagram D, Plate XXII) again outcrops in the bluff
north of the San Pedro Valley, but is covered in this bluff by a sandy stratum
between it and the soil. This gravel stratum runs along the bluff near the surface
until it reaches a point about two hundred yards north of the valley, where it
suddenly dips at an angle of 45° for eight feet, resting all the while on the eroded
surface of the lower San Pedro strata. Again changing its dip to normal, it disap-
pears under the detritus at the mouth of a short ravine. The unconformable position
of the upper gravel on the lower gray sand is very apparent a few yards south of
the ravine, where fragments of the lower San Pedro strata are found in the upper
gravel. After the deposition of the lower San Pedro beds there came a period of
uplift, during which they were eroded; then came a period of depression, during
which the upper San Pedro beds were deposited on the eroded surface of the
lower series.
A heterogeneous series of strata, composed of alternating beds of sand and
gravel, occurs above the gravel stratum at the ravine and to the north of it.
These overlying beds dip gently to the north, but the series does not decrease
in thickness to the north for the reason that other strata begin near the top of
the bluff, and thus make a nearly horizontal surface to the top of the series, which
is overlain by soil to the thickness of from two to ten feet. The lower strata
along this bluff are of fine sand, fossiliferous in places. Near the top of the
bluff, however, the strata are composed of coarse material, a distinct layer of gravel
cemented with lime and containing many well preserved fossils forming the top layer.
This top stratum first appears at the top of the bluff about one hundred feet south of
the ravine. From this point south of the ravine it can be traced north along the
bluff near the top, around the north end of the bluff, and back again on the west side
of this promontory for several hundred feet. About six feet below the top gravel
stratum is another layer rich in fossils. The beds below these last two are sand and
gravel deposits of varying composition, nearly all, however, fossiliferous. Some of
these lower strata show sand-dune bedding, while others are horizontal. This alter-
nation of bedding would indicate a period of alternating conditions of elevation and
ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO.
27
depression during the beginning of the epoch in which the upper San Pedro beds
were deposited. The same sequence of strata as in the north end of the bluff occurs
across the little valley to the west. The strata extend toward the west, but just how
far it is not possible to determine. All the fossils labeled "San Pedro" and "Lum-
ber yard " are from the upper San Pedro strata in this locality, and many fine
specimens have been obtained during the past few years. A great many shiploads of
material have been hauled away from the bluffs as ballast by the coaling vessels
docked at the port of San Pedro.
The uppermost gravel stratum of the ujiper San Pedro series appears to be
laid down nearly horizontally and almost continuously over the whole of the lower
or fifty-foot terrace of San Pedro Hill.
The following species from the type locality of the upper San Pedro series
were collected at the north end of the San Pedro bluff, near the lumber yard, one-
half mile north of the valley:
List of Fossils from the North End of the San Pedro Bluff.
(P indicates species found living at San Pedro; N indicates species found living only north of San Pedro;
S indicates species found living only south of San Pedro; E indicates extinct species or those not known as living.)
Amianlts callosa, P
Anijulus hiUloni, P
Anomia lampn, P
Area labiata, S
Asiarte branneri, E
Cardium corbis, N
Gardium elalum, S
Cardium proccrum, S
Cardium quadriiicnaritim,
Chama exoijyra, P
Chama pfllucida, P
CUdiophora punctata, P
Corbula luteola, P
Cryptomya californica, P
Cuminriia californica, P
Diplodonta orbf.lla, P
Diplodonta serricala, S
Donax californica, P
Donax Irevir/ata, P
Glycymi'ris barbarensis, E
Olycymeris septcntrionalis,
Hinnitcs giganteus, P
Lcevicardium subslriatum,
Lazaria subqnadrala, P
Leda taphria, P
Lucina acutilineata, P
Lucina californica, P
Lucina nuttalli, P
Lucina tcnutsculpta, P
Aincta insessa, P
Am,CBa pelta, P
Amtca spectrum, P
PELECYPODA.
Lyoiisia californica, P
Macoma indentata, P
Macoma inquinata, P
Macoma naxuta, P
Macoma var. kelscysi, S
Macoma secla, P
Maclra californica, P
Mactra catilliformis, P
Mactra exolrta, S
Mactra falcala, P
Mactra hemphilli, E
Metis aha, P
Modiola recta, P
Mytilus edulis, P
Nucula supraxtriata, N
Ostrea lurida, P
Panopea gcnerosa, P
Pecten dentatus, S
Pecten latiauritus, P
Pecten var. fragiliK, E
Pecten var. monotimeris,
Pecten newsomi, E
Pecten stibnodosvs, S
Pecten ventricosus, P
Periploma argentaria, P
Petricola carditoidea, P
Petricola denliculata, S
Pholadidea penila, P
GASTROPODA.
Actai07i punctoccelata, P
Actce07> trankii, S
Amphissa corrugata, P
Platyodon cancellatus, P
Pododesmufi macroschisma,
Psammobia cdentula, ?
Psephis tantilla, N
Sanguinolaria nuttalli, P
Saxidomus arat-us, P
Semele decisa, P
Se.mele pulchra, P
Siliqua lucida, P
Siliqua var. nuttalli, N
Solen roKaceus, P
Solen sicarius, P
Tagelua californianu.% P
Tapes lactneata, P
Tapes siaminea, P
Tapes lenerrima, P
Tellina bodegensis, S
Tellina rubescens, S
Tivela crassatelloides, P
Tresus nuttalli, P
Venericardia barbarensis,
Venus fiuctifraga, P
Venus gnidia, S
Venus neglecta, S
Venus simillima, P
Venus succincta, P
Yoldia cooperi, P
Zirphcea gabbi, E
Amphissa versicolor, P
Bittiuni asperum, P
Bittinm /ilosum, P
28
CALIFORNIA ACADEMY OF SCIENCES.
BMiuni quadrifilatum, P
Bittium rugaium, P
Bitlium williamno7u, ?
Bulla punctulala, S
Bulla quoyi, P
Caecum cali/orniciitn, P
Cacum crebricinclum, P
C'alliostonia annulalum, P
Calliotiio77ia ca7ialiculafu)n, P
C'allios(o77ia costah(7/i, P
C'alUontoma yi:m77iutalU7n, P
Calliosloma tricolor, P
Cancfllaria cooperi, P
Cancellaria craw/ordiana, P
Cancellaria trilonidea, E
Cerithide.a catifor/iica, P
ChlorostoTTia aurcoliiicliini, P
Chloroiit077ia Jutifbrale, P
ChloroM077ia var. subapurlum, P
C'hlorosi07>ia galllna, P
Chlorostoma mo7Uereyi, P
Chlorot!l07na var. ligidat^nn, P
Chorus belcherl, P
ClathurMa co7iradiana, E
Clipidella hhnaculata, N
Clipidelta callo7>iargi7iala, P
Colu77ibella chrysalloidea, P
Columbella gausapata, P
Columbella var. carinala, P
Columbella minima, E
CohimJiella var. prcectirsor, S
Columbella hiberosa, P
Co7ius cali/or/iicus, P
CoralUophila 7iux, S
Crepidula aculeaia, P
Crepidula adunca, P
Crepidula Tiavicelloides, P
Crepidula onyx, S
Crepidula rugosa, P
Crucibulum spiiwsum, P
Cylichna alba, P
Drillia hemphilli, S
Drillia iiier7)iis, P
Drillia johnso7ii, E
Drillia var. pP7iicillala, P
Drillia pudica, S
Drillia torosa, P
Erato colum,bclla, P
JCtUi7)ia ha-^tata, S
Eulima 7nicatis, P
Eupleura muriciformis, S
Di'iitalium hi'xagoiitim,
Euph'ura var. curia, E
Eissuridca asptra, V
Fisituridra i7uequalis, S
Fissuridea murina, P
Fissurella volcano, P
Fusus barbarensis, E
Fusus luteopictus, P
Fusus robustus, P
Galerus 7nammillariit, P
Hami7iea vircscims, P
Helix sp. iudet., ?
Isapis fenestrata, P
IslmochitOTi regularis, P
Lacuna compacta, N
Lacu7ia porrecla, N
Lacuna nolidula, P
Leplothyra carpenteri, P
Littorina pla7iaxis, P
Littori7ia scutulata P
Macron kellettii, S
Mopalia ciliata, P
MaTigilia hooveri, E
Mangilia striosa, P
Margarita var. knechti, E
Margarita var. pedrocma, E
Margi7iell.a jcwetti, P
Melampus ollvaceus, P
Mitra maura, P
Monoceros eiigonatum, P
Monoceros lapilloides, P
Murex fesiivus, P
Murex foliatus, N
Murex leea7ius, S
Murex 7no7ioceros, S
Murex trialatus, P
Jfassa californiana, P
Nassa cerritensis, E
Nassa fossata, P
Nassa insculpta, C
Nassa 7)iendica, P
Nassa var. cooperi, P
Nassa perpi7iguls, P
Nassa tegula, P
Nassa var. hooveri, S
Natica lewisii, P
Neverita recluziana, P
Ocinebrafoveolata, P
Ocinebra interfossa, P
OciTiebra var. aipera, P
Ocinebra ca7icelli7ia, S
Ocinebra pe.rila, P
CRUSTACEA.
Bala7ms concavus, P
SCAPHOPODA.
Dentaliu77i pseudohexagonu7n. ?
ECHINOIDEA.
Eckinarachnius excentricus, P
PISCES.
Urolophus halh'ri, ?
Oci7iehra poulvmi, P
Odostomia tenuis, P
Olivella biplicata, P
Olivella i7itorta, P
Olivella pedroa7iii, P
Opalia borealis, P
Pachypoma iniKjuale, P
Paludestrina curia, E
Paludestri7ia stokesi, E
Phasianella co7npta, P
Pisa7iia fortis, E
Planorbis tumidus, S
Pla7iorbis vermicularis, N
Pleurotoma carpenteriana, P
Pleurotoma cooperi, E
Pleurotoma perversa, N
Pleurotoma tryo7iia7ia, P
Pomaulax u7idosus, P
Prie7ie orego7iensis, P
Puncturella cucullata, N
Purpura crispata, N
Purpura saxicola, P
Pyratnidelta var. variegata, S
Ranella cali/or/iica, P
Bissoa acutelirata, S
Scala bellastriata, P
Scala crebricostata, P
Scala he7nphHli, E
Scala hindsii, P
Scala indianorum, P
Scala tincta, P
Se.rpulorbis sejuamigerus, P
Sipho7ialia kellettii, P
Spiroglyjihus lituella, P
Terebra si7nplex, P
Tor7iati7ia cerealis, P
Tornaii7\a culcitella, P
Trivia californica, P
Triton gibbosus, S
Tro}iho7i multicostatus, N
Turbonilla auraniia, P
TurboniUa la77iinata, P
Turbonilla lowei, E
Turbo7iiUa stear7isii, S
Tttrbo7iilla subcuspidata, S
TurboniUa lenuicula, P
Turritella cooperi, P
Turritella jetvetti, E
Vitrinella willia7nso7ii, P
Volvari7ia varia, P
Dentaliu77i se)7iipolitu77i, S
ARNOLD— THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 29
Resume.
Total number of species 252
Pelecypoda ^5
Gastropoda 1^1
Scaphopoda ^
Echiuoidea 1
Crustacea 1
Pisces *
Living at San Pedro 1"2
Percentage of fauna 68.2
Living only north of San Pedro 15
Percentage of fauna 6.1
Living only south of San Pedro 36
Percentage of fauna 14.2
Extinct species 24
Percentage of fauna 9.5
Questionable 4
Percentage of fauna 1-6
The fauna of the upper San Pedro series as afforded by the beds near the
himber yard is of a character more nearly resembling that found living at the present
time on the coast two or three hundred miles further south. Not only is there a
large percentage of species now living only south of San Pedro, but of the species
living at San Pedro many are southern forms. Several of the northern forms
remained during the period of deposition of the upper San Pedro series, but in greatly
diminished numbers. Of the extinct forms most are new species or varieties which
may be found upon a more extended examination to be living. Faunal evidence
leads to the conclusion, therefore, that the climatic conditions on the coast near San
Pedro during the period of deposition of the upper San Pedro series were as warm,
if not warmer, than those of the present time. The change from the boreal condi-
tions of the upper Pliocene epoch to the tropical or semitropical conditions of the
Pleistocene was not sudden, but took place rather gradually, as is shown by the
transition fauna of the lower San Pedro deposits.
The upper San Pedro stage described in this paper is separated from the
lower San Pedro deposits for the following reasons: First, there is an unconformity
between these upper beds and the underlying formations at all of the localities
examined. Secondly, the upper San Pedro beds differ lithologically from the lower
San Pedro strata; the former being largely gravels, while the latter are of gray sand.
Thirdly, the difference in the fossils of the two horizons is very marked. Many
found in the lower series are not found in the upper, and many of the species in the
latter are never found in the former. Fourthly, the upper series has a semi-tropical
fauna, while that of the lower series approaches the semi-boreal.
The upper San Pedro beds do not represent the top of the Pleistocene. The
fauna of these upper beds, although having many species in common with the living
fauna of the same locality, is still quite distinct. This would suggest a period of
considerable length since the deposition of the strata. The number of distinctly
southern forms living at San Pedro during the period of deposition of the upper
beds also shows that there has probably been a change in climatic conditions since
30
CALIFORNIA ACADEMY OF SCIENCES.
that time. A raised beach unconformable with the upper San Pedro strata at Dead-
man Island shows that there have been orographic movements since the upper San
Pedro beds were deposited. All of this evidence, then, leads to the conclusion that
there has been a sufficient lapse of time since the deposition of the upper San Pedro
strata, to admit of marked faunal and orographic changes.
The upper San Pedro series is well developed on Los Cerritos Hill, where the
typical fossiliferous gravels of the upper San Pedro formation overlie unconformably
the brown, tilted sandstones which form the major portion of that hill. A little above
H (diagram E, Plate XXIII), the gravel stratum has a dip of 4° due south. Below
the gravel stratum is a thin bed of sand, which is also very fossiliferous. At G the
gravel stratum is only a few feet below the surface of the hill, but near the top of the
hill this stratum is covered by a deeper deposit of sands and sandy soil. The dip of
the stratum at K is N. 85° W. at an angle of from 12° to 15°. At K the gravel is
overlain by a deposit of fine, unfossiliferous sand four feet thick.
At all the localities on Los Cerritos Hill where the upper San Pedro beds are
exposed, the underlying formation is a series of sands and conglomerates. No fossils
were obtained in the underlying series of rocks, but they are probably of the lower
San Pedro series.
It will be noticed, on looking at the contours on diagram E, Plate XXIII, and
observing the dips at the different places, that the dip of the gravel stratum conforms
very nearly to the slope of the hill. There is a fault at H, which cuts the upper San
Pedro stratum. The sand deposits above the gravels in a few places are probably
what is left of layers of sand which once covered the whole area. On the flanks of
the hill, both to the northwest, where the Los Angeles Terminal Railway cuts the
ridge, and toward the south, where the ocean has exposed the beds, sands overlie or
replace the gravel stratum. This fossiliferous upper San Pedro stratum is at no place
on Los Cerritos Hill more than a few feet thick. W. S. T. Smith' thinks that per-
haps this hill is wave built, but a careful examination shows that it is the result of
an orogenic movement which has taken place since the lower San Pedro beds were
deposited there. This is shown by the contortion of the lower formation, and by the
steep dips of the uppermost layers, which conform almost exactly with the slope of
the hill. This orogenic movement has taken place since the upper San Pedro series
was deposited, and is evidence in favor of the theory that the upper San Pedro beds
are at least older than the latest Pleistocene.
List of Species Collected in the Upper San Pedro Beds at Los Cerritos.
Atigena cerrilensis
Amianlis callosa
Angulus buttoni
Anomia lanipe
Aslarte hranntri
Cardium corbis
PELECYPODA.
Cardium datum
Cardium procerum
Cardium quadrigenarium
Chama exogi/ra
Chnina pellucida
Corbula luteola
Crypiomya californica
Donax laevigata
Qlyrymeris barharensis
Glycymeris sppte.ntrionalis
Hinniies giganteus
Lmvicardium substriatum
' Topographic Study of the Islands of Southern California. By W. 8. T. Smith. Bull. Dept. Oeol., Univ. of Cal., Vol. II, 1900, p. 224.
ARNOLD — THE PALEONTOLOGY AND STRATIGKAPHY OF SAN PEDKO.
31
Leila taphria
LithophfKjiis jilumula
Lucina califoniica
Lucina nuttalli
Macoma indeniata
Macoma inquinnta
Mricoma nnsuta
Macoma vai". kelsryi
Macoma secla
Mactra calilliformis
Mactra falcala
Metis alia
Modiola fornicaia
Modiola recta
Nucula supra.itriata
Oslrea lurida
AcnKJ^a insessa
Acmaa pelta
Amphissa corrugata
Amphissa versicolor
Bittium ijuadrifilatum
Bittium rugatum
Bulla punclidata
Coecum californicum
Ccecum crebricinclum
Calliostoma caiialiculatum
Calliosloma coslaiuvi
Calliostoma gemmulatuni
Calliosloma tricolor
Cerithidea californica
Chlorostoma funebrale
Chlorosloma var. subaperlum
Chlorostoma var. ligulatum
Chorus belcheri
Clipidella bimaculata
Clipidella callomarginata
Coliimbella gausapata
Columbella var. carinata
Columbella luberosa
Conns californicus
Crepidula adunca
Crepidula dorsata
Crepidula navicelloides
Crepidula onyx
Crepidula rugosa
Crucibulum spinosum
Drillia cancellata
Panopea generosa
Pccten latiauriius
Pecten var. fragilis
Peclen var. monotimeris
Pecten neicsomi
Peclen ventricosus
Periploma argeniaria
Petricola cardiioides
Petricola denticulata
Pholadidea penita
Platijodon cancellatus
Psephis tantilla
Sanguinolaria nullnlli
Saxidomus aratus *
Semele decisa
GASTROPODA.
Drillia hemphilli
Drillia inermis
Drillia var. ptnicillata
Drillia torosa
Eulima micans
Pissitridea aspcra
Fissuridea iiuBqualis
Fissuridea murina
Fissurella volcano
Fusus luteopictus
Hipponyx cranioides
Lacuna compacta
Lacuna porrecta
Leplothyra bacula
Lillorina scutulata
Lucapina crenulata
MangiUa angulata
Mangilia interlirata
MangiUa striosa
Margarita var. pedroana
Melampus olivaceus
Monoceros engonatum
Murex festivus
Nassa cali/orniana
N^assa cerritensis
Nassa fossata
Nassa mendica
Nassa var. cooperi
Nassa perpinguis
Nassa tegula
Natica lewisii
CRUSTACEA.
Balanus concavus
SCAPHOPODA.
Dentalium hexagonum
ECHINOIDEA.
Echinarachnius exccnlricus
Semele pulchra
Silit/ua liicida
Solen sicarius
Tagelus californianus
Tapes lacineata
Tapes ataminea
Tapes tenerrima
Tt'llina bodegensis
Tellina idfi
Tivela crassatelloid's
Tresus nuttalli
Venus neglecta
Venus simillima
Venus succincta
Zirpihcea gabhi
Neverita recluziana
Ocinebra var. aspera
Ocinebra var. cerritensis
Ocinebra poulsoni
Olivella biplicata
Olivella intorta
Olivella pedroana
Pleuroloma pierversa
Ranella californica
Scala hindsii
Scala indianorum
Scala tincta
Serpulorbis squamigerus
Sigaretus debilis
Siphonalia kellettii
Spiroglyphus litttella
Taranis slrongi
Terebra simplex
Tornatina culcitella
Trophon cerritensis
Turbonilla aurantia
Turbonilla crebrifilata
Turbonilla laminata
Turbonilla lowei
Turbonilla similis
Turbonilla stcarnsii
Turbonilla subcuspidata
Turbonilla ienuicnla
Turbonilla tridenta
Turritella cooperi
Volvaria varia
This fauna consists of one hundred and sixty species, of which sixty-four are
pelecypods, ninety-two are gastropods, one is a scaphopod, one is a crustacean, and
32
CALIFOKNIA ACADEMY OF SCIENCES.
one is an echinoderm. It is similar to the upper San Pedro fauna of the beds at the
north end of the San Pedro bluff; and has even a more southern character than that
fauna. The great preponderance of pelecypods over gastropods as regards the num-
ber of individuals is noteworthy in the Los Cerritos deiwsits. It is such a fauna as
would be found on a low, sandy coast.
There is an extensive exposure of upper San Pedro strata in the bluff to the
south and southeast of Long Beach. A typical section of the bhiff is represented by
the section exposed at B (diagram E, Plate XXIII), about one and one-half miles
east of the Long Beach wharf. The sequence of the beds is as follows :
Soil, grading into uustratified brown sand 12 feet
Thin beds of light gray sand 8 feet
White wind-bedded sand 15 feet
Brown sand, with horizontal bedding 6 feet
Total thickness 41 feet
All of the strata from this point west to A (diagram E, Plate XXIII), the end
of the bluff, dip gently westward, the lower strata disappearing successively under
the level of the beach. The fossils in this series occur only in local deposits, most of
them being found in lens-shaped pockets in the white sand layer. There is a very
fossiliferous deposit at E, which extends for three hundred feet along the base of the
cliff. At B (diagram E, Plate XXIII), also, there is a small deposit of sand con-
taining only Ostrea lurida. It is probable that for the most part these strata were
deposited during a period of sand-dune and estuarine conditions along this part of the
coast. The dominating shells in these deposits are Ostrea lurida, CryiAomya califor-
nica, Tagelus californianus, and other forms which inhabit lagoons and shallow
waters. The following fossils were obtained from the fossiliferous bed at the base of
the bluff at E, southeast of Long Beach.
List of Fossils from the Beds Southeast of Long Beach.
Anomia lampe
Balanus concavus
Crepidula rugoaa
Columbella var. cariuala
C'ardium procerum
Cardium fjnadrigenarhim
Crucib II In m spinas u m
Chionc simillima
Chlorostoma funehrale
Cryptomya cali/ornica
Conus californicus
Donax IcevigcUa
Dentalium hexarjonum
Drillia var. peniciUala
Fissu ridca inierj ualis
Olyrymeris seplenlrionalis
Lucina ntittalli
The deposits of
although no fossils have
deposits around the base
Lucina cali/ornica
Liitorina scutulata
Lunatia lewisii
Leda taphria
Monoceros engonatum
Maconia sccta
Macoma nasula
Nevcrita reculziana
Nassa perpinguis
Nassa cerrilensis
Nassa tegula
Nassa me.ndica
Nassa var. coopcri
Nassa fossata
Nassa californiana
Ostrea lurida
Olivelta biplicala
Dominguez Hill are probably of
been found in them. Lithologically
of Los Cerritos Hill.
Olivella pcdroana
Olivella intorta
Pecten ventricosus
Pecten latiatiriltis
Pecten var. monotimeris
Pleurotoma carpentcriana
Pteronotus festivus
Serpulorbis squamigrrus
Scala tincta
Terebra simplex
Tagelus californianus
Turritella cooperi
Tellina bodeginsis
Tivela crnssatelloidcs
Tapes slaviinra
Vcnericardia barbarensis
Zirphaia gabbi
upper San Pedro age,
they are similar to the
AKNOLD — THE PALEONTOLOGY AND STRATIGEAPHY OF SAN PEDRO.
33
Raised Beach Formation. — The recently raised beach on the north end of
Deadmau Island (see diagram B, Plate XXII) shows that the period of uplift which
followed the deposition of the upper San Pedro beds is not yet finished. This raised
beach contains many fossil shells in a perfect state of preservation, all of them retain-
ing their original color, which suggests how recently this uplift has taken place.
List of Fossils from the Raised Beach, North End of Deadman Island.
Cryplomija cali/oraica
Donax Icevigala
Lcevicardhun substriatum
Lucina cnlt/ornica
Liiclna nntlalli
ilacoma inquinala
Acmna spectrum
Acmcea pelia
Bulla nebulosa
Calliostoma canaliculatum
Cerithidea californica
Chlorostoma funehrale
PELECYPODA.
Macoma nasuta
Macoma secla
Mactra catilliformis
Mactra falcata
Mytiius edulis
Pecten iatiaurilus
GASTROPODA.
ColumbeUa gausapala
ColumbiUa var. carinaia
Conns californicus
Crepidula rugosa
Credbulum spinosum
Dr'dlia var. penicillnta
Peclen var. monolimeris
Pecten ventricosus
Petricola carditoides
l^apes staminea
Tellina bodegensis
Fissurella volcano
Xassa fossata
Nassa var. cooperi
Olivella biplicata
OliveUa intorta
These species are all found living in the waters adjacent to Deadman Island
at the present time, and the raised beach specimens are in nearly as good a state of
preservation as the living shells.
5. Post-Pleistocene Deposits.
Overlying the Pleistocene of Deadman Island, and all along the San Pedro
terrace, is soil containing many shells, in fact, in places; it is made up almost entirely
of shells. These are the remains of ancient Indian kitchen-middens. Ashley ^
describes as Quaternary a layer of shells found in the lower terrace of San
Pedro Hill. After examining the fossils collected by him, and also visiting the
locality from which they came, the writer is convinced that these deposits are simply
the shells brought there by the Indians, for the association of species is not such as
would be found at any one place on the beach; rocky shore and lagoon shells being
found in about equal quantities. At every place where these shell deposits in the soil
have been examined by the writer they have been found to contain pieces of charcoal,
bones of mammals, and other evidences of refuse heaps. These kitchen-middens are
common at many places along the coast. Those at Port Harford are over six feet in
thickness and have been mistaken by some collectors for Pleistocene strata.
The shells in these kitchen waste heaps are of a kind that would be used for
food, and include such species as Haliotis cracheroidii, Pecten aciuimlcatus, Cliione
succincta, Tivela crassatelloides, Tapes staminea, Saxidomus aratus, etc. All of the
specimens of Haliotis so far recorded from the Pleistocene, with the exception of one
1 The Neocene Stratigraphy of the Ssuta Cruz Mountains of California. By George H. Ashley. Proc. Cal. Acad. Sci., 2d Ser.,
Vol. V, 1895. pp. 353-356.
( 5 ) September 25, 1902.
34 CALIFORNIA ACADEMY OF SCIENCES.
Haliotis fulgens found by the writer in the upper San Pedro conglomerate of Dead-
man Island, and another in the Pleistocene at Spanish Bight, San Diego, have been
taken from these Indian kitchen-middens.
6. Alphabetic List showing the Distribution of Species in the Vicinity
OF San Pedro.
In order to avoid any mistake, a brief description of the locality represented by
each column in the following list is here given.
The second column, marked " Deadman Island " under upper San Pedro
series, refers to the gravel stratum which extends across Deadman Island about six
feet below the surface, and which is shown as the upper San Pedro series in diagram
B, PL XXII. (See also diagram U, PI. XXIII.)
The third column, marked " Lumber Yard," refers to the sand and gravel
deposits at the north end of the San Pedro bluff; these beds are designated as upper
San Pedro series in diagram B, PI. XXII.
The fourth column refers to Los Cerritos Hill, which is shown on diagram E,
PI. XXIII, and diagram 0, PI. XXII. The fossils reported in this column come
from the gravel and sand strata at the localities H and K on that hill.
The fifth column, designated as "Crawfish George's," refers to the deposits
on the northeast side of the mouth of the ravine which empties into the ocean at
Crawfish George's. (See diagram E, PL XXIII.)
The sixth column, marked " Deadman Island " under lower San Pedro series,
refers to the gray sand deposits lying between the Pliocene and upper San Pedro
gravel strata; this deposit is designated as lower San Pedro series in diagram £,
PL XXII.
The seventh column, designated as "San Pedro Bluffs," refers to the lower
San Pedro strata which lie above the Pliocene on the south and below the upper San
Pedro series on the north, in the water front bluff east of San Pedro; these deposits
are designated as lower San Pedro series in diagram I), PL XXII.
Column eight, marked " Deadman Island " under Pliocene, refers to the
brown san(L "Cryptodon beds," and contact stratum of Deadman Island; these
deposits are designated as Pliocene in diagram B, PL XXII.
The ninth column, marked "Timm's Point" under Pliocene, refers to the
brown sand deposits of Timm's Point and between that jwint and the middle of the
railroad cut and grade up the bluff in the southeastern portion of San Pedro; these
deposits are designated as Pliocene in diagram J), PL XXII.
ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO.
35
Alphabetic List Showing the Distribution op Species in the Vicinity' of San
Pedro.*
(E indicates species which are extinct; X Indicates species living at San Pedro; S indicates species living only
south of San Pedro; N indicates species living only north of San Pedro; C indicates species living only at Catalina
Island; R stands for rare; M stands for medium abundant; C stands for common.)
PELECYPODA.
Aligena cerritensis, sp. nov
Amiantis callosa Conkad
Angulus huitoni Dall
A nomia lanipe Gray
Area labiala Sowerbt
Astarie (Crassinella) branneri, sp. nov
Bornia relifera Dall
Callista subdiaphana Cabpentek
Callisia subdiaphana var. pedroann, var. nov.
Callista newcombiana Gabb
Cardium corbis Martyn
Cardium elalmn Sowerby
Cardium procerum Sowerby
Cardium quadrigenarium Conrad
Chama exogyra Conrad
Chama pellucida Sowerby
Clldiophora punctata Conrad
Cooperella subdiaphana Carpenter
Corbula luteola Carpenter
Cryptomya californica Conrad
Cumingia californica Conrad
Diplodonta orbella Gould
Diplodonta serricata Reeve
Donax californica CONRAD
Donax laevigata Desha YRS
Glycymeris barbarensis Conrad
i3
E
X
X
X
s
E
N
N
E
X
N
S
S
X
X
X
X
X
X
X
X
X
s
X
X
E
Pleistocene.
Upper Sail Pedro.
11
■a rt
R
R
R
R
R
R
M
R
R
R
C
R
M
R
M
K
C
C
R
R
R
R
C
R
R
C
R
C
C
R
C
R
C
M
M
R
C
C
R
R
M
M
C
R
tft -
« SI,
fcEf
cu o
R
M
M
R
R
R
R
M
R
Lower
San Pedro.
T3 rt
M
R
R
M
M
R
R
R
M
R
R
R
R
R
R
M
M
M
C
R
M
a n
c o
* This list has been kept open until the time for sending the manuscript to presB, and contains a few species vbich are not given in
the general discussion, although the descriptiona of all species mentioned are given in Part II
36
CALIFORNIA ACADEMY OF SCIENCES.
a
>
2
Pleistocene.
Pliocene.
Upper San Pedro.
Lower
San Pedro.
(13 V
P4
4
O
h
■a B
0
Ph 3
i a
OlycytHCTts septeulTioiialis Midden dorf
N
X
X
X
c
N
X
X
N
X
N
X
X
X
X
X
X
X
X
N
X
X
X
s
X
X
X
X
s
X
s
X
N
X
N
X
R
R
R
R
R
R
c
R
R
M
R
C
M
R
R
R
c
M
c
C
M
R
R
C
R
R
R
C
C
M
C
M
C
R
C
R
R
R
R
R
R
R
M
R
R
C
R
C
M
M
R
C
c
c
R
R
R
R
R
R
R
R
R
M
R
R
M
R
R
R
M
R
R
R
R
R
R
R
R
M
R
R
c
R
C
C
0
M
M
M
R
R
R
R
R
R
C
R
R
R
R
R
R
R
c
c
c
c
M
R
R
1
R
C
C
C
C
M
C
JCcllici Iciperousii Deshayes.
Kennerlia filosa Carpenter
Lftvicdrditt^n subsirHiiutn Conrad
Ledcc fos<^ct Baird
I/cdct 7niuttict var. pr<ECUTS0T, var. nov
R
C
Z/Uchi(t californictt Conrad
Lyonsia californica Conrad
Macoma indrviata Carpenter
MacoTfia nasutci var. helseyi Dall
Macoma secia Conrad
Macoma yoldiformis Carpenter
Mactra {Spisula) catillifornw Conrad
Maclra exokta Gray
Mactra [Spisula) falcala Gould
Mactra hemphilli Dall
Metis alia Cokrad
Modiola fornicata Carpenter
Modiola recta Conrad
Mrerella salmonea Carpenter
Mytilus edulia lANnmvs
ARNOLD — THE PALEONTOLOGY AND STEATIGBAPHY OF SAN PEDEO.
o7
Mytilimeria niittalli Conrad
Necera peciinata Carpenter
Nucula {Acila) casirensis Hinds
Nucula siiprasiriata Carpenter
Ostrea liirida Carpenter
Panoniya ampla Ball
Panopea generosa Gould
Pecten (Patinopecten) caurinus GotJLD
Pecien (Pecten) denlatus Sowerby
Pecten (Chlamys) hasiatus Sowerby
Pecten (Chlamys) herkeus Gould
Pecten (Chlamys) hericeus Yar. strategns Dall.. .
Pecten (Chlamys) jordani, sp. nov
Pecien latiauritus Conrad
Pecten latiauritus var . fragilis, Yar. hoy
Pecten latiauritus Yar. monoiimeris Conrad
Pecten (Plagioctenium) newsomi, sp. nov
Pecten stearnsii Dall
Pecien (Nodipecten) subnodosus Sowerby
Pecten (Plagioctenium) ventricosus Sowerby....
Pecten (Plagioctenium) ventricosus Sowerby var.
Periploma argentaria Conrad
Petricola carditoides Conrad
Petricola (Petricolaria) cognata C. B. Adams...
Petricola denliculata Sowerby
Pholadidea penita Conrad
Platyodon cancellatus Conrad
Pododesmus (Moitia) macroschisma Desha yes...
Protocardia centifilosa Carpenter
Psammobia edentula Gabb
Psephis aalmonea Carpenter
Psephis tantilla Gould
Rceta undulata Gould
Rupellaria lamellifera Conrad
Sanguinolaria nuttaUi Conrad
Saxidomus aratus Gould
a u
wo
X
X
X
N
X
N
X
N
S
X
N
N
E
X
E
X
E
E
S
X
E
X
X
X
s
X
X
X
X
?
c
N
X
X
X
X
Pleistocene.
Upper San Pedro.
P
K
M
K
E
M
E
M
E
M
B
E
Lumber
Yard.
J
C
c
C
E
E
E
C
C
E
E
E
M
E
E
E
C
M
E
R
R
M
E
E
E
C
M
M
E
E
E
R
E
E
M
E
c
0
rt O
E
E
M
M
E
E
Lower
Sau Pedro.
E
E
R
E
E
E
E
M
E
E
E
E
E
E
R
R
M
E
R
R
R
R
E
E
R
E
E
as
R
E
E
C
M
M
M
ga
E
38
CALIFORNIA ACADEMY OF SCIENCES.
Semele decisa Conrad
Semele pulchra Soweeby
Semele pnlchra v&r. monlereyi, var.uov.
0 c
CUTS
a,
X
X
N
Septifer bifurcatus Conrad X
Siliijua iiicida CoNRAD
Siliqua patula var. nuttalli Conrad
Solen rosaceus Carpenter X
X
N
Solen sicarius Gould X
Tagelus californianus Conrad X
Tapes laciniata Carpenter X
Tapes staminea Conrad X
Tapes tenerrima Carpenter X
TMina bodegensis Hinds X
Tellina ida Dall X
Tellina rubescetis Hanley S
Thracia Irapezoides Conrad E
Thyasira bisecta Conrad N
Thyasira gouldii Philippi X
Tivela crassatelloides Conrad X
Tresus nuttalli Conrad X
Venericardia barbarensh Stearns X
Venerkardia venlricosa Godld N
Venus (Chione) flucti/raga Sowerby X
Ve.nus (Chione) gnidia Broderip & Sowerby S
Venus (Chione) neglecta Sowerby j S
Venus (Chione) simillima Sowerby t X
X
X
X
X
X
Venus (Chione) succincta Valenciennes
Verticordia novemcostala Adams & Reeve.
Yoldia cooperi Gabb
Yoldia scissurata Dall
Zirphoea gabbi Tryon
Pleistocene.
Upper San Pedro.
M
R
R
C
C
R
R
R
C
Lower
San Pedro.
■25
M
C
B
.CO
M
R
M
R
R
C
R
C
R
C
C
C
R
R
R
R
C
C
R
M
C
R
M
R
C
M
C
R
C
R
M
R
R
C
C
cd o
S-o
R
R
M
M
R
R
R
R
R
R
C
M
R
R
R
R
C
M
R
R
R
a m
to"
in
M
M
R
M
M
M
R
C
R
C
C
R
M
C
R
R
M
C
AKNOLD — THE PALEONTOLOGY AND STKATIGKAPHY OF SAN PEDRO.
39
GASTKOPODA.
Acmcea depicta Gould
Acmma insessa Hikds
Acmcea inslabilis Gould
Acmcea mitra Eschscholtz
Acmcea pateacea Gould
Acmcea pelta Eschscholtz
Acmcea spectrum (Nuttall) Keeve
Actceoii ( Rictaxis) punctoccelata Carpenter.
Actceon iraskii Stearns
Admete gracilior Carpenter
Amphissa corrugala Eeeve
Amphissa ventricosa, sp. nov
Amphissa versicolor Dall
Beta fidicula Gould
Bcla sanctce-monica: sp. nov
Bittium asperum Gabb
Bittium californicum Dall & Bartsch
Bittium filosum Gould
Bittium (jvadrijiiatum Carpenter
Bittium rugaitnn Carpenter
Bittium wiUiamsoni, sp. nov
Bulla punctulata A. Adams
Bulla quoyi Gray
Ccecum californicum Dall
Ccecum crebricinctum Carpenter
Ca'cum magnum Stearns
Calliostoma annulatum Martyn
Caltiosloma caniculatum Makiyn
Calliostoma costatum Martyn
Calliostoma gemmulatum Carpenter
Calliostoma tricolor Gabb
Canccllaria cooperi Gabb
Cancellaria craw/orcliana Dall
Cancellaria tritonidca Gabb
3
s
X
N
X
X
X
X
X
9
E
X
E
X
N
E
X
E
N
X
X
V
s
X
X
X
;
X
X
X
X
X
X
s
E
Pleistocese.
Upper San Pedro.
5a
K
K
M
E
M
K
R
C
R
C
E
C
E
E
E
M
M
M
M
M
E
E
E
E
M
E
R
R
C
R
E
C
E
R
R
"I
" 9.
E
M
R
C
C
C
E
E
M
C
M
C
R
R
R
Lower
San Pedro.
M
E
E
E
E
E
E
R
R
E
M
R
M
M
C
C
R
R
M
R
M
E
M
M
C
M
C
E
M
R
11
M
E
E
40
CALIFORNIA ACADEMY OF SCIENCES.
Cerithidea californica Haldemann
Chlorosloma aurcoUncium Forbes
Chlorostoma hrunneum Philippi
Chlorostoma funebrale A. Adams
Chlorosloma funrbrale var. subapertum Carpenter..
Chlorostoma (jallina Forbes
Chlorostoma monlerejii Kiener
Chlorostoma (Omphalius) virklulum var. iUjulatum
Menke
Chorus belcheri Hinds
Chrysodomus, sp. indet
Chrysodomus rectirosiris Carpenter
Chrysodomus tahulatus Baird
Clalhitrella conradiana Gabb
Ciypidella bimacjilata Dall
ClypideUa callomaryinata Carpenter
Columhella ( Aslyris) californiana Gaskoin
Columbella (^iBsop«s) chrysalloidea Carpenter.
Columbdla {Aslyris) gausapala Gould
Columbella (Aslyris) gausapala var. carinata Hinds
Columbella {Anachis) minima, sp. uov
Columbella {^Esojnis) oUlroydi, sj). uov
(■oliimbella solidula var. praicursor, var. uov. . . .
Columbella (Aslyris) luberosa Carpenter
Conus californicus Hinds
Coralliojihiia ii ax IvEEVE
Crepidula aeulcala Gmelin
Crepidula adwnca Sowerby
Crepidula dorsala Broderip
Crepidula grandis Middendore
Crepidula navicelloides Nuttall
Crepidula onyx Sowerby
Crepidula rugosa Nottali
Grucibulum spinosum Sowerby
Cryptochilon slclleri Middendore
>
5
X
X
X
X
X
X
X
X
X
N
N
X
9
N
X
X
X
X
X
E
E
S
X
X
s
X
X
X
N
X
s
X
X
N
Pleistocene.
upper San Pedro.
an
E
K
R
K
K
E
E
C
E
C
M
E
M
E
C
M
3^
c
M
M
M
E
E
M
M
E
E
E
C
E
C
E
E
C
C
E
C
M
C
c
E
E
E
C
E
E
E
E
C
E
C
M
E
E
E
C
M
E
C
C
E
E
C
E
E
E
M
E
C
M
E
M
0
M
Lower
San Pedro.
a
ti
S2
E
E
E
E
M
M
C
M
E
E
E
E
M
E
M
M
E
M
E
E
R
E
1.1a
S5
M
E
E
M
E
E
M
R
M
E
E
M
E
M
M
M
M
a .
a
E
E
E
E
M
C
C
E
C
M
a o
H
M
U
AKNOLD— THE PALEONTOLOGY AND STEATIGllAPHY OF SAN PEDIIO.
41
6
>
Pleistocene.
Pliocene.
Upper San Pedro.
Lower
San Pedro.
n£
la's
5^
in
.s
St
u
a
si
TS tSt
a
o
u
s
ai
Cylichna alba Brown
X
X
E
9
N
S
X
X
E
E
N
S
X
X
S
S
X
s
E
X
s
X
X
X
X
X
X
X
X
X
9
^ !
i
N
X
K
M
K
B
K
R
E
M
R
M
E
R
R
R
R
R
C
C
C
B
R
R
R
R
R
B
R
R
B
B
C
E
M
B
E
E
E
B
E
M
C
C
E
M
E
M
E
M
M
E
R
M
G
E
C
M
C
E
C
C
E
M
C
E
M
M
E
R
R
R
E
E
R
C
R
R
R
M
B
R
M
R
R
C
R
B
M
R
M
M
M
R
M
R
B
C
C
E
Cyprcea spadicea Gray
Diastoma, sp. iiidet
Drillia cancellata Carpenter
DrilUa hemphilli Stearns
Drillia incrmis Hinds
Drillia inermis var. penicitlata Carpenter. .
Drillia johnsoni, sp. nov
Drillia merriami, sp. uov
Drillia montereyensis Stearns
Drillia pudica Hinds
Drillia torosa Cakpentek
M
Erato colnmbella Menke
Eulima falcata Carpenter
Eulima hastata Sowerby
Eulima micans Carpenter
Eupleura muriciforinis Broderip
EupUura muriciformis var. ciirta, var. nov
Fissuridea aspera Esch.scholtz
Fissuridea incequalis Sowerby
Fissuridea miirina (Carpenter) Dai.l
FissurcUa volcano Reeve.
Fusus barbarensis Trask ....
M
Fusus luteopictus Dall
Fusus robustus Trask
Fusus rugosus Trask
Gadinia reticulata Sowerby . .
Galerus mammillaris Broderip
Haliotis fulgeus Philippi
*
Haminca virescens Sowerby.
Helix (Epiphragmophora), sp. indet.
Hipponyx antiqnaius LiNNa:us
Hipponyx cranioides Carpenter....
Hipponyx lumens Carpenter
(6)
c t
'iV.ci. o>;
ono
42
GALIFOKNIA ACADEMY OF SCIENCES.
Isapis feneslrnla Carpenter
Ischnochlton rrgularis Cakpenter
Ivara terricula (Carpenter) Dali. & Bartsch.
Lacuna compacla Carpenter
Lacuna porrecla Carpenter
Lacuna solidula (Loven) Carpenter
Lamellaria steanisii Dall
Lcptolhyra bacula Carpenter
Leptolhyra carpenter! Pilsbry
Lcplothyra paucicostata Dall
a
X
X
s
N
N
X
X
X
X
X
Liltorina planaxh (Nuttall) Philippi j X
Littorina scutulata Gould X
Lucapina crenulala Sowerby X
Macron kelletlii A. Adams S
Macron lividus A. Adams X
Mangilia angulata Carpenter N
Mangilia hoover!, sp. nov E
Mangilia interfossa var. pedroana, var. nov E
Mangilia interlirata Stearns ' X
Mangilia oldroydi, sp. nov E
Mangilia painei, sp. uov E
Mangilia sculpturata Dall X
Mangilia striosa C. B. Adams X
Margarita obtabilis var. knechti, var. uov E
Margarita oplahilis var. nodosus, var. nov E
Margarita parcipicta var. pedroana, var. uov E
Margarita pupilla Goold N
Marginella jewettii Carpenter X
Melampus olivaceus Carpenter X
Mitra maurn Swainson X
Milramorphafilosa Carpenter X
Milramorpha intermedia, sp. nov E
Monoceros engonalum Conrad X
Monoceros lapilloides Conrad X
Mopalia ciliata Sowerby X
Pleistocene.
Upper San Pedro.
K
K
R
M
3^
J
a;
O
M
K
M
B
C
E
E
E
E
E
M
E
E
E
E
E
E
R
E
E
E
M
E
E
C
E
E
C
E
E
E
n o
u u
E
R
E
E
M
M
Lower
Sail Pedro.
R
E
M
R
R
E
E
R
R
M
E
E
R
E
C
R
E
E
E
M
M
E
B. 3
M
E
C
M
C
E
C
M
M
M
E
•O CO
E
ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO.
43
a
>
5
Pleistocene.
Pliocene.
Upper San Pedro.
Lower
San Pedro.
■a a
St
V
o
BJ O
a
o
h
•O B
1^
to
So
c'o
pa.
Murex (Pleronotus) festivus Hinds
X
N
X
s
s
X
X
E
X
c
X
X
X
X
s
N
X
X
X
X
X
X
E
X
N
s
E
C
V
X
X
X
N
X
X
R
R
R
R
M
M
C
M
E
M
M
R
R
R
R
M
R
C
c
R
C
C
M
C
R
M
R
C
C
c
M
R
C
C
R
M
R
C
R
C
M
R
C
M
R
R
C
M
R
C
C
R
M
C
R
R
M
M
R
R
M
R
R
C
M
C
M
E
R
M
R
R
E
E
R
M
R
C
R
R
R
C
C
c
E
R
R
R
E
E
R
E
M
E
R
E
c
E
M
C
C
E
E
E
E
E
E
M
R
R
0
R
R
M
M
R
M
R
R
R
Murex (Pterohytis) foliatus MaRTYN
Murex (Pterohytis) nnttalU Conkad
Murex (Cerostoina) monoceros Sowerby
Murex trialatus Sowerby
Nassa californiana Conrad
Nassa innculpta Carpenter
M
Nassd Tneiidicci var. cooperi Forbes
M
^assa perj>inguis Hin'ds
R
N^assa tegulci Reeve
Nalka clausa Broderip & Sowerby
R
Natica (Lunatia) lewisli Gould
Neverita recluziana Petit
N^orrisia norrisii Sowerby
Ochiebra barbarensis Gabb,
Ocinebra foveolata Hinds
Ocinebra interfossa Carpenter
Ocinebra keepi, sp. nov
Ocinebra lurida Middendorf
Ocinebra lurida var. a^pera Baihd
Ocinebra lurida var. cancellina Philippi
Ocinebra lurida var. ■munda Carpenter
Ocinebra micheli Ford
Ocinebra perita Hinds
Ocinebra pouhoni Nuttall
Odostomia (/ouUlii Carpenter
Odonlomia nuciformis ya,T. avellana Carpenter
Odostomia tenuis Carpenter
Olivella biplicata Sowerby
R
44
CALIFOKNIA ACADEMY OF SCIENCES.
Olivella intoria Carpknteb
Olivella petlroana Conrad
Opalia hori'alis Gould
Opalia creniloide.s var. insculpta Carpentbr. .
Pachypoma incequale Martyn
Paludestrina curia, sp. nov
Paltidnslrina stokesi, sp. nov
Phaxianella r.ompia Gould
Phorcus pulligo Martvn
Phyna helerostropha Say
PIsania fortis Carpenter
Planorbis tuinidus Pfeiffer
PlanorhU verinicularis Gould
Pleurotoma (Borsonia) bartschi, sp. nov
P kuroioma (Dolichotoma) carpenteriana Gabb
Pleurotoma (Dolichotoma) cooperi, sp. nov....
Pleurotoma (Borsonia) dalli, sp. nov
Pleurotoma (Borsonia) hooveri, sp. nov
Pleurotoma (Leucosy rinx) pedroana, sp. nov. . .
Pleurotoma perversa Gabb
Pleurotoma (Drillia) rniaudi, sp. nov
Pleurotoma (Spirolropsis) smithi, sp. nov
Pleurotoma (Dolichotoma) tryoniana Gabb...,
Pomaulax undosus Wood
Priene orerjonensis KedfielD
Puncturella cucullata Gould
Puncturella galeata Gould
Purpura crispata Chemnitz
Purpura saxicola Valenciennes
Pyramidilia conica var. variegata Carpenter..
Ranella californica Hinds
Rissoa aculelirata Carpenter
Scala bellnstriata Carpenter
Scala crebricostata Carpenter
Scala hemphilli Dall
CM
X
X
X
X
X
E
E
X
X
X
E
S
N
E
X
E
E
E
E
X
E
E
X
X
X
N
N
N
X
s
X
s
X
X
E
Pleistocene.
Upper San Pedro.
c
R
M
M
R
E
3^
c
E
R
E
E
E
C
E
M
M
M
R
K
E
E
E
E
E
E
C
E
E
M
E
R
C
rt o
M
E
E
E
M
Lower
San Pedro.
c
M
E
M
E
E
E
E
E
M
E
R
E
•a .to
Ok 3
in
C
M
E
E
E
E
R
E
E
E
E
Pliocene.
M
M
M
R
M
E
M
C
M
M
go
ARNOLD — THE PALEONTOLOGY AND STKATIGKAPHY OF SAN PEDKO.
45
Scala hindsii Carpenter
Scala indianorum Carpenter
Scala iincta Carpenter
Sella assimilala C. B. Adams
Serpulorbis squamigerus Carpenter
Sigaretus debilis GocLD
Siphonalla kellettii Forbes
Solariella cidaris A. Adams
Solariella peramabilis Carpenter
Spiroglyphtis lituella MoRCH
Styliferina ienuisculpia Carpenter
Taranlf strong! sp. nov
Terebra (AcusJ simplex Carpenter
Thalotia caffea Gabb
Tornaiina cerealis Gould
Toriiatlna culcitella Gould
Tornaiina eximia Baird
Tornaiina harpa Dall
Triforis adversa MoNTAonE
Trivia californica Grav
Trivia solandri Gray
Tritonium gibbosus Broderip
Trophon (Boreotrophon) cerriiensis, sp. nov
Trophon (Boreotrophon) gracilis Perry
Trophon (Boreotrophon) muliicostatus Eschscholtz.
Trophon (Boreotrophon) pedroanus, sp. uov
Trophon (Boreotrophon) scalarl/ormis Gould
Trophon stuarti Smith
Trophon orpheus var. prcecursor, var. uov
Trophon (Boreotrophon) ienuisculpia Carpenter. ..
Trophon (Boreotrophon) iriangulatus Carpenter..
Turbonilla adleri (Dall & Bartsch), sp. nov
Turbonilla arnoldi (Dall & Bartsch), sp. nov
Turbonilla aurantia Carpenter
Turbonilla crebrijllata Carpenter
X
X
X
X
X
X
X
X
c
X
1
E
X
X
X
X
X
X
N
X
X
s
E
X
N
E
N
N
E
E
X
E
E
X
X
Pleistocene.
Pliocene.
Upper San Pedro.
K
K
E
M
E
C
C
E
M
E
E
M
E
E
E
E
K
E
E
B
E
M
E
E
•5 «
Ui
ca o
u V
M
M
E
R
M
E
E
E
Lower
San Pedro.
E
E
E
E
E
E
E
M
E
E
M
E
E
E
E
E
C
C
E
M
E
R
E
E
E
a. 3
M
E
E
R
M
M
M
R
R
•O CO
E
R
E
K
R
M
E
R
R
C
C
E
E
46
CALIFORNIA ACADEMY OF SCIENCES.
d
>
5
Pleistocene.
1
Pliocene.
Upper San Pedro.
IvOwer
San Pedro.
at
c .
a
(J .
3>.
St
■S"
a o
c a
Q
e .
Die
c
2-d
! TJ W
Tufhonilhi ijibbosci Carpenter
X
X
E
E
S
X
X
s
s
X
X
N
N
X
E
J
X
X
X
?
J
J
9
X
X
X
J
N
E
E
M
R
K
R
R
E
C
C
R
R
R
C
R
R
M
R
R
R
C
R
R
R
C
C
R
R
R
R
M
C
M
M
R
R
M
R
R
R
R
R
R
R
R
R
E
R
R
C
M
E
E
E
E
C
C
C
E
E
R
R
R
E
R
R
R
R
C
R
M
c
c
R
C
R
E
Turbonilla laminaia Carpenter
Turhonllla lal'ifundla (Dall & Bartsch), sp. nov. . .
Turbonilla lowei (Dall & Bartsch), sp. nov
Turbonilla pentalopha (Dall & Bartsch), sp. nov. .
Turbonilla similimis C . B. Auams
7'urbonilla stearnsii (Dall & Bartsch), sp. nov ....
Turbonilla lenuicula Gould
Turbonilla iorquata Gould
Turbonilla torquata var. slylina Carpenter
Turbonilla tridenia Carpenter
Turrildla cooperi Carpenter
c
Turrilella jewelii Carpenter
Vitrin('.lla williattisoni Dall
Volvarina varia Sowerby
Volvula cylindrica Carpenter
ANTHOZOA.
Caryophyllia arnoldi Vaughan
Caryophyllia californica (Vaughan), sp. nov
Caryophyllia pedroensis (Vaughan), sp. nov
Paracyathun pedroensis (Vaughan), sp. uov
ECHINOIDEA.
Echinarachnitts exceiUricua Eschscholtz
Stronqylocunlrotus franciscanus Agassiz
Stro7iyylocentrotus purpuratus Stimpson
BRYOZOA.
Bryozoan remains
BKACHIOPODA.
Terebratalia amilhi, sp. nov
ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO.
47
SCAPHOPODA.
Cadulus nitenlior Carpenter
Dentalium indianorum Carpenter
Denialium hexagonum Sowerby
Dentalium pseudohexaijonum Dall
Dentalium semipolitum Brodeeip & Sowerby
CRUSTACEA.
Balanus concavus Bronn
Cancer breweri Gabb
PISCES.
Urolophus halleri ( ?) Cooper
>
iJ
X
N
X
X
E
R
Pleistocene.
Upper San Pedro.
C
M
R R
M
M
" ?.
00
R
C
Lower
San Pedro.
•O 00
R
M
C
R
K
ft- 3
R
M
M
Pliocene.
a o
Chapter II,
THE UPPER PLIOCENE AND PLEISTOCENE FORMATION OF
OTHER LOCALITIES OF THE PACIFIC COAST.
In discussing the occurrence of the Pleistocene deposits at other points along
the Pacific Coast it will be necessary, in most instances, to quote the observations of
others, as the writer has visited only a few of these localities.
The writer examined a raised beach at Blakeley Point, opposite Seattle, Wash-
ington, during the summer of 1900. It consists of sandy deposits lying horizontal
upon the upturned and eroded edges of the Astoria Miocene strata. This beach and
one or two others in the same vicinity are about ten or twelve feet above the level of
Puget Sound, showing a total thickness of about ten feet; they are of late Pleistocene
age, undoubtedly later than the last ice age of that country. The following species
of marine mollusks in a rather poor state of preservation were obtained from the Point
Blakeley raised beach:
Macoma inquinata Purpura crispata Saxidomus aratus Tapes slaminea
Several deposits of a similar nature have been reported by J. P. Kimball' in
the same vicinity. Dr. Kimball is of the opinion that there has been a recent eleva-
tion of the shores of the Sound of at least twenty-five feet. This uplift has taken place
since the glacial drift was deposited in that region. Dall- reports a Pleistocene
deposit, overlying beds of Pliocene age, from thirty to forty feet above the sea, near
Bruceport, Washington.
Mr. H. W. Turner of the United States Geological Survey collected several
specimens of sandstone containing the borings and shells o( Fholadidea penita Conrad,
from an elevation of fifty feet above tide water, at Fort Ross, Sonoma County, Califor-
nia. Pholadidea penita not occurring previously to the Pleistocene, this evidence
shows that there has been a post-Pleistocene uplift of at least fifty feet at Fort Ross.
On the flanks of several of the little valleys draining into the Bay of San Fran-
cisco are deposits known to be of post-Pliocene age. Whitney describes some of
these de230sits, and makes correlations which are important, if correct. He says: ^
" A post-Tertiary deposit made up of beds of gravel, sand, clay, and oyster
' Physiographic Geology of the Puget Sound Basin. By J. P Kimball. Am. Geol., Vol. XIX, 1897, p. 231.
- Correlation Papers. Neocene. By W. H. Dall and G. D. Harris. Bull. U. 8. Oeol. Sur. No. 84, p. 228, 1892.
a Geological Survey of California. By J. D. Whitney, State Geologist. Geology, Vol. I, p. 102, 1866.
( 48 )
AKNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 49
shells rests horizontally upon the upturned edges of the Cretaceous at several local-
ities around Benicia. These are similar to the beds noticed as occurring on the
shore between Martinez and Bull's Head Point, which contain fragments of bones of
large animals and rolled Tertiary shells. Similar beds, with oysters, were observed
on San Pablo Bay between Point Pinole and the Embarcadero; at this locality the
beds containing oysters, which rest horizontally on upturned strata of the Tertiary,
are elevated twenty feet above the level of the waters of the bay. At Benicia, also,
there has been an elevation of several feet since the oyster beds were deposited.
With the shells of oysters, those of other species, all now living in the waters of the
bay, are found. These deposits evidently belong to the post-Pliocene, and they are
of the same age as the beds of gravel, with boulders of gray .sandstone, containing the
bones of the mastodon and horse, which occur at Bottle Hill near Benicia."
The Pleistocene deposits on the shore of San Pablo Bay between the Union
Oil Refinery and Point Pinole have been visited by Dr. Merriam and the writer.
The deposits, which rest on the upturned edges of the San Pablo strata, consist of
horizontally bedded layers of sand, gravel, and clay. Teeth of the mammoth, and
bones of the giant sloth and extinct bison have been found in these Pleistocene layers
by Dr. Merriam. In certain places the Pleistocene layers consist almost entirely of
oyster and mussel shells.
List of Fossils from the Pleistocene Deposits on San Pablo Bay between the
Union Oil Refinery and Point Pinole.
Ostrea lurida Oslrea conchaphila Mylilus edulis Tagelus cali/ornianus
The character of these Pleistocene strata and of their fauna leads the writer to
coiTelate them with the upper San Pedro series.
Deposits of soft yellow sand resting on the Mei'ced (Pliocene) strata in the
vicinity of Lake Merced on the San Francisco peninsula have been assigned to the
Pleistocene by Lawson' and Ashley.^ The line of demarkation between the Plio-
cene and Pleistocene at some places mentioned by these authors seems to be in doubt.
Both are agreed that there is an unconformity between the two series, and Ashley
thinks that there was a period of subaerial erosion between them.
The Pleistocene deposits mentioned by Ashley^ as occurring along the tops of
the sea-cliflfs from Montara Point south are partly of fresh-water and partly of marine
origin. Those at Purissima are certainly of marine origin, for pholas borings have been
found in the old beach-line on which they were deposited. The deposits along the upper
edge of this same terrace in the vicinity of Halfraoon Bay are of fresh-water origin,
and are very recent. The Haliotis mentioned by Ashley as occurring in these
deposits are from Indian kitchen-middens, common at many places along the Califor-
nia coast. Similar kitchen-middens near San Mateo have been reported as Quai'ter-
uary b}' the same writer.
' The Geology of the San FranciBco Peninsula. By A. C. Lawson. 15th Ann. Eep. U. S. Geol. Surv., 1895, p. 463. et seq.
» The Neocene Stratigraphy of the Santa Cruz Mountains of California. By G. H. Ashley. Proc. Cal. Acad. Sci,, 2nd ser., Vol. V,
1895, p. 347, et scq.
' Op. cit., p. 349.
C ' ) September 26, 1902.
50 CALIFORNIA ACADEMY OF SCIENCES.
In the region surrounding Carmelo Bay^ are numerous terraces strewn with
boulders and pebbles, more or less cemented together, and in several cases with the
adjoining rock surfaces showing borings which resemble those of Pholadidea penita.
No fossils have been found in these deposits, but Lawson believes them to be of
Pleistocene origin. He also believes that there was an interruption in the Pleistocene
sedimentation, during which time orogenic movements took place. His conclusions
are based on the finding of an unconformity between two of the terrace formations in
a section north of Abalone Point.
Fairbanks^ tells of a large area of Pleistocene sediments lying west of Corrali-
tos Creek and north of the summit of the ridge. The beds are horizontal and consist
of indistinctly stratified and slightly consolidated sand. This sand formation reaches
a maximum thickness of about three hundred feet. Fragments of shells are found
over the surface of the deposits up to an elevation of nine hundred feet. The only
shells positively identified from the surface of the beds are:
Chlorostoma hrunneum Haliotis (!) Lunalia lnwisii Myiilus californicus Purpura canaliculata
This fauna is similar to that of the Indian kitchen-middens found at so many
places along the coast, and it seems probable that the shells are from deposits of this
kind. Their occurrence on the surface would add weight to this theory. Another
Pleistocene area in this Point Sal district is at the head of the valley north of the
dairy, and consists of fragments of bituminous shale, and a deposit of calcium carbon-
ate containing casts of Crepidula rugosa and a species of Purpura. Fairbanks says
these beds are similar to those of Point Loma, near San Diego, " even to the presence
on the surface of small concretionary nodules of sand cemented by iron oxide." ^
From Mallagh Landing, two miles southeast of Port Harford, to Pismo, and
from Surf to Santa Barbara the sea-clififs are capped by deposits of sand and gravel
which are probably of Pleistocene age. No fossils were found in any of the localities
visited; but in several places, noticeably northwest of Pismo, pholas-bored pebbles
were found at the contact between the Pleistocene sands and the underlying eroded
Miocene shale, thus showing the marine origin of the Pleistocene deposits.
Santa Barbara and Vicinity.
The Packard's Hill deposits are the most important of the fossiliferous
beds in the immediate vicinity of Santa Barbara. Packard's Hill is a ridge
about three hundred feet in height, which begins a short distance northwest of
the western end of the beach boulevard, and extends for nearly a mile due north.
Its eastern slope is almost precipitous, and outcrops of the fossil-bearing strata are
found over the whole slope. The best outcrops, and the one from which all the fossils
were obtained by the writer, are about two-thirds of the way up the hill. The hill
consists of layers of fine, soft, light yellow sand and marl, which is hardened in places
' The Geology of Carmelo Bay. By A. 0. Lawson. Bull. Dept. Geol., Univ. Cal., Vol. I., p. 62, el seq.
2 The Geology of Point Sal By H. W. Faiibanks. Bull. Dept. Geol., UniT. Cal., Vol. II., 1806, p. 6-8.
3 Of. cit., p. 8.
ARNOLD — THE PALEONTOLOGY AND STBATIGEAPHY OF SAN PEDKO. 51
by the lime leached from shells. The clip of the beds is nearly due south at an angle
of 15°. The hardened strata are darker colored than the softer beds, and as a rule
are more fossiliferous. The fossils in the soft strata are very fragile, but by using
care some fine specimens may be obtained fi'om them.
The fauna of the Packard's Hill deposits is similar to that of the upper
horizon of the San Diego formation, and is probably equivalent to that part of the
Pliocene which is missing between the Deadman Island Pliocene and the overlying
lower San Pedro series (Pleistocene). The close relation between the Pecten hellus
Conrad found in the Packard's Hill Pliocene and the Pecten hempliilli Dall of the
upper horizon in the San Diego formation is an indication of a more or less close
relation between the two formations. Pecten hellus, Terehratalia hemphilli, Laqueus
jeffreysi, and Vemts perlaminosn are the most characteristic specimens found at Pack-
ard's Hill.
A bluff nearly thirty feet in height begins just west of the western end of the
beach boulevard at Santa Barbara, and extends southwest along the ocean. For
the first eighth of a mile, or along the edge of the first cove, the bluff consists
of rather evenly bedded, soft, brownish yellow, sandy marl, which dips S. 30'^ E.
14°. Ai'ound the point one-eighth mile southwest of the bath-house the bluff
consists of irregularl}' bedded gravels and sand, which seem at some places to rest
unconformably upon the fossiliferous marl beds, although false bedding is so prevalent
in the deposits along this bluff that any positive evidence as to the conformability of
the strata was hard to obtain. Further southwest along the coast, the gravels and
sand rest upon the upturned and eroded edges of the contorted Miocene shales. At
one place about half a mile south of the bath-house, where these Pleistocene sands
and gravels rest upon the Miocene shales, the Pleistocene deposits were impregnated
with asphaltum. In this same place a fragment of the fossiliferous sandstone, similar
to that which is found at the northern end of the bluff near the bath-house, was
found in the Pleistocene gravels; thus giving evidence that there are two distinct
horizons in the Pleistocene along this bluff.
Alternating strata of sand and gravel, showing false bedding, are exposed in
the sea-cliff east of the Santa Barbara wharf. A sti-atum of shell fragments was
found near the western end of this cliff, but no specific determination of the fossils
could be made on account of their poor state of preservation. The strata of this bluff
are similar to, and probably contemporaneous with, the late Pleistocene strata in the
bluff southwest of the bath-house.
52
CALIFORNIA ACADEMY OP SCIENCES.
List of Fossils Collected from the Pliocene and Pleistocene Formations of
Santa Barbara, California.
II
no.
■a .a J
ss
o y
J= o
u
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Admefe (jrnclUor Carpenter
Amphistid corruiffitit Reeve
Mitramorpha iniermedia^ sp. nov
Modiola J'ornicata Carpenter
Balanuti concavus Broxn
Bfla fidicula Gould
Nasna mevdica Gould
Natica clatisa Broderip & Sowerby
X
Bittiu m aAperum Gabb
Bitiium qundr iff latum Carpenter
Bryozoa sp. (?)
Ocinebra lurida var. aspera Baird
Ocinebra perita Hinds
Odostomia nuciformis var. avellana Car-
penter
Calliostoma gemmuJatum Carpenter
Odostomia gouldii Carpenter
Ollvella hipUcata Sowerby
Columbdla (Astyris) ganmjmia Gould. . .
Columhe.Ua (Astyrix) (jausapata var. cnri-
iicitft Hinds
Panopea generosa Gould
X
Pecten bellus Conrad
X
Pecten caurimis Gould
X
Columbella (Astyris) tnh-rom Carpenter.
Pecten hastaius Sowerby
X
Pecten jordani^ sp. nov
X
X
Pododesinus macroschisma Deshayes
Protocardia centijiiosa Carpenter.
Psfipkis salmonea Carpenter
Diastoma, sp . (?)
X
X
Puncturella cuculnta Gould
X
Olottidia albida Hinds
Strongylocentrotus purpuratita Stimson. . .
Terfibratrtl'nt h'^mphiUi Dall
X
Laqueus jf'ffrojsi { ?) Dall
Tornatina culcitella Gould
Trophon gracilis Perry
Trophon orphens var. prcecursor, var. nov.
Turbonilla tridenta Carpenter
Vewricardia barbarctisis Stearns
Venericardia venlrirosa Gould
Venus pe)'lat)iiuo.sa Conrad
Lucina californica Conrad
Macoma sp. ( ?)
M^diigilici cuufulutci Carpenter
X
X
X
Mangilia interfossa v&t. pedrocmajXar. no v.
Recognizable fcssils are found only in the few beds of soft, brownish-yellow
marl at the northeastern end of the bluff west of the bath-house. The lowest strata
exposed near the bath-house consist almost wholly of bryozoan remains, among which
are scattered a few shells. The bryozoan remains give place to sand in the beds a
ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 53
few feet above. The large shells in the strata are poorly preserved, but the smaller
fossils, especially the gastropods, are abundant and well preserved.
The fauna of the beds west of the bath-house is similar to that of the lower
San Pedro series (lower Pleistocene) of Deadman Island, and these Santa Barbara
beds are probably contemporaneous with the lower San Pedro deposit of Deadman
Island. Several nearly perfect tests of Strongylocentrotus pu7yuratus were found in
the bath-house strata, the first tests of this species that have been recorded from the
Pleistocene. Echinarachnius excentricus. was also found in the same bed. The strati-
graphic relation between the Packard's Hill and bath-house beach fossiliferous deposits
was not obtained, but the former are probably the older strata, although both may
belong to the same series and be nearly contemporaneous.
Lithologically the two beds are somewhat similar, but faunally they differ con-
siderably. The absence of Pecten hellus, Terehralalia hempMlli, Laqueiis jeffreysi and
Pecten opuntia from the bath-house beach strata; and the absence of the two species
of echinoderms and many species of gastropods from the Packard's Hill beds, are the
noticeable differences between the two faunas.
Whitney mentions the following loaalities, besides those already cited, where
Pleistocene deposits were found by the State Survey: At Hill's Ranch,' about six
miles west of Santa Barbara, "the bituminous slate is covered unconformably, as at
Santa Barbara, by a heavy deposit of post-Pliocene age, which here attains a thickness
of from eighty to one hundred feet. The bituminous slates, which are highly con-
torted and turned upon edge, lie nearly on a level with the ocean; and on their
edges rests a body of soft, arenaceous, and loose gravelly materials, sometimes very
slightly consolidated, and in which are long fissures filled with asphaltum." On the
southwestern face- of Santa Barbara Island is a raised beach thirty feet above tide
level, containing marine shells, which Whitney thinks is the same formation as that
found at Santa Barbara. Near the Santa Maria River the hills of Miocene shale are
capi^ed with horizontal post-Pliocene deposits.^
Dr. Stephen Bowers* describes the Pleistocene of Santa Rosa Island from
notes taken by Dr. L. G. Yates: "On the north side of the island, about ten miles
from the wharf, and near the mouth of Soledad Canyon, there is a fine exposure of
strata consisting of about ninety feet of post-Pliocene deposits, containing fossil bones
of vertebrates and at one place fossil Physas, at a depth of some seventy-five feet below
the surface. This deposit is horizontal and overlies strata of older rocks, probably
Pliocene, which dip 13° northeast, and contain Pectens and Turbinelias in abundance."
Judging by the fauna of the Pleistocene deposits on Santa Rosa Island, they
are probably of fresh-water origin. An elephant's tooth and other elephant remains
are reported by DalP as having been found by W. G. Blunt and Voy on Santa
Rosa Island.
Ventura. — The most striking thing in relation to the geology of the vicinity of
1 Geological Survey of California. By J. D. Whitney, Slate Geologist. Geology, 1865, Vol. I, p. 132.
- Op. at., p. 183.
3 Op. cit., p. 137.
* Santa Rosa Island. By Rev. Stephen Bowers. Smithsonian Report, 1877, p. 317.
« Correlation Papers. Neocene. By W. H. Dall and G. D. Harris. Bull O. S. Geol. Snr., No. 84, 1892, p. 217.
54 CALIFORNIA ACADEMY OF SCIENCES.
Ventura is the great development and the high elevation above sea-level of the
Pleistocene dejiosits in that locality. The terrace on which the city is located and
the hills immediately back of the city are of Pleistocene origin. This is shown by
the marine fauna collected at different localities in the vicinity.
The fir.st locality visited was along the course of the old irrigating ditch, which
runs at an elevation of about two hundred and fifty feet above sea-level on the eastern
side of the valley west of Ventura. The hills along which this ditch runs rise to
over five hundred feet in height, and are composed of fine, soft, yellow sandstones
which dip south at an angle of 50 . These sandstones were examined for about
one-half mile north of Ventura along the ditch. This exposure represents a thick-
ness of at least one thousand feet. Several of the strata were fossiliferous and
yielded a fauna similar to that of the Pleistocene of San Pedro. The upper beds, or
those nearest the ocean, contained a fauna similar to the upper San Pedro series,
while that of the beds further down in tiie series contained such species as are com-
monest in the lower San Pedro series. The lower beds were characterized by the great
abundance of TurrlUUa coo'peri. An outcrop in a ravine near the new hospital on the
north side of Ventura contained a fauna simij^r to that of the upper beds along the ditch.
There is an exposure of fossiliferous Pleistocene strata between Barlow's ranch
house, three miles east of Ventura, and a prominent point, called "The Peak," north
of the house. "The Peak" has an elevation of one thousand and seventy feet, ac-
cording to the United States Coast and Geodetic Survey. The highest point at which
fossils were obtained was about two hundred and fifty feet below the summit, but the
same formation extends to the top, and probably comprises all of the sediments form-
ing the elevated ridge which lies back of Ventura from the ocean, and extends
parallel with the coast for several miles east of Ventura.
The fossiliferous strata exposed were about twenty-five feet thick, and con-
sisted of five or six layers of shells from three to nine inches in thickness, separated
by fine, soft, light yellow .sand layers. Tlie whole series was unconsolidated, except
for local hardenings in the shell layers, and was oxidized but little. The dip of the
strata was from 30° to 40° south, which corresponded nearly to the general slope
of the main ridge, whose axis was parallel with the coast, and of which "The
Peak" was the highest point.
The fauna collected consisted of about fifty species, all of which are common
to the San Pedro series. The similarity between this fauna and that of the upper San
Pedro series, and the incoherency and lack of oxidation of the matrix, leave little
doubt as to the age of these beds. They are of Pleistocene origin, and, moreover, are
synchronous with the upper San Pedro series. Their elevation of about eight hun-
dred feet above the sea-level seems remarkable, but only confirms the theory of the
recent great elevation of the coast of California from San Francisco southward.
ARNOLD- THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO.
55
List of Fossils Collected from the Pleistocene Formations in the Vicinity of
Ventura, California.
en
0 u
03
bet;
■CO
in
ti
is
(0
bo
c .
I.
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
ActtToii (Rictaxii) punctoccekUa Carpenter
AiKjulus buttoni Dall
Monoceros engonalum Conrad
X
X
Bela fidicula Gould
X
Bittimn Uf^peruyii Gabb
A^evcTtta rccluziana Petit
X
Cadulus nitentior Carpenter
Neverita rccluziana var. alta Dall
Ocinehra lurida var. asprra Baird
X
Cancellaria trUonidea Gabb
X
Chione succincla Valenciennes
Chlorosloma funebrale A. Adams
Chorus belckeri Hinds
Odostomia nuci/ormis var. avellana Car-
penter
X
Chrysodomus labulatus Baiud
Odostomia tenuis Carpenter
Olivella biplicata Sowerby
X
Columbella (Astyris) gausapala Gould. ..
Columbella (Astyris) gausapaia var. cari-
nata Hinds
X
Olivella intorta Carpenter
X
Olivella pedroana Conrad
Pecteti latiaurilus yar . monotimeris Conrad
Pecten ventricosus Sowerby . , ...
Crepidula adunca Sowerby
Cryptomya cali/ornica Conrad
X
CyUchna alba Brown
Denlalium hexagonum Sowerby
Pleurotoma carpenteriana Gabb
Purpura saxicola Valenciennes
X
X
Donax hevigaia Deshayes
Rissoa acutclirala Carpenter
X
Drillia hemphilli Stearns
Drillia inermis Hinds
X
Drillia inermis var. pcnicillala Carpenter
Scala tincta Carpenter
Echinarachnius excentricus Eschscholtz. .
Tapes tenerrima Carpenter
Eulima micans Carpenter
Eiilima haslaia Sowerby
Lacuna compacta Carpenter
Littorina scutulata Gould
X
Mncoma nasuia Conrad
Turbonilla laminata Carpenter
Turbonilla, four sp. ( ? )
Mactra catilliformis Conrad
Mangilia angulata Carpenter
Mangilia sp. (?)
Watts and Cooper give lists of fossils from several localities in Santa Barbara,
Ventura and Los Angeles counties' which suggest the Pleistocene age of the deposits
' The Gas and Petroleum Yielding Formations of the Central Valley of California. By W. L. Watts. Bull. Cal. State Mining
Bureau, No. 3, 1884.
Lists of Fossils Identified by Dr. J. G. Cooper. Oil and Gas Yielding formations of Los Angeles, Ventura, and Santa Barbara
counties. By W. L. Watts. Bull. Cal. State Mining Bureau, No. II, 1897, pp. 79-87.
56
CALIFORNIA ACADEMY OF SCIENCES.
from wbicli the fossils were taken. The faunas are generally so small, and the strati-
graphic notes so incomplete, that it is not possible to make any definite correlations
between these deposits and the different horizons of the San Pedro series.
Port Los Angeles. — The writer has obtained the following species from a hard,
sandy stratum underlying more than a hundred feet of soft, sandy deposits in the mouth
of the canyon at the end of the large wharf at Port Los Angeles, near Santa Monica:
Asli/ris gausapala
Beta sanche-monkcE
Bittium aspe.rum
Nassa mcndica var. cooperi
Nasaa pcrpinguis
Nevi-rila rccluziana
Olivella biplicala
Olivella intorta
Osirea lurida ( ?)
Pisania fortis
Pleuroloma carpenieriana
Plcnrotoma perversa
Tapes slaminea
Turritella cooperi
Trophon scalari/ormis
Vencricardia venlricosa
The stratum from which the above fossils were obtained is probably Pleisto-
cene, corresponding to the lower San Pedro series of Deadman Island, for lithologically
and faunally the strata are quite similar. The overlying beds are soft and unfossilifer-
ous, and lie slightly unconformably on the lower fossiliferous stratum; and although
they contain no fossils, still, from lithological and stratigraphical reasons, it is probable
that they are equivalent to the upper San Pedro deposits. These Pleistocene strata ex-
tend down the coast from the great wharf to about one-half mile below Santa Monica.
8an Clemente Island. — The post-Pliocene deposits of San Clemente Island are
small. W. S. T. Smith' says that they consist of fine sand and rolled pebbles, and
have a maximum thickness of only ten feet. Lucina californica is the only fossil
shell reported from these deposits.
Neivport. — Much of the coast line from Long Beach to San Diego consists of
more or less elevated deposits of Pleistocene age. Deposits of Pleistocene age have
been examined by W. L. Watts in the vicinity of Newport, Orange county.^ About
a mile north of the town of Newport is a formation of soft sandstone and yellowish
clay-shale, with layers of hard calcareous strata, and some strata which appear to be
made up largely of diatomaceous material. These deposits contain the following
species, which have been identified by Dr. J. C. Merriam:
Anomia lampe Crucibulnin spinosum Placunanomia macrosehisma
Cardiumpanamense[^=C. procerum} Macoma inquinata Potnaidax undosus
C'hione similUma Ncverita reciuziana Tapes slaminea
Chione succincta Pecten ccquisulcaliis [)^P. ventricosusi Zirphcea crispata [r=Z. Gabbi]
The fauna given above shows that this deposit is equivalent to the upper San
Pedro series.
The oil-sand and sandstone west of the inner bay at Newport contain the
following species:^
BiUiuin aspcrum
Bryozoau remains
Crepidula aduncn
Lucina californica
Macoma inquinata
Monoccros enyonutum
Nassa fossata
Nassa perpinrjuis
Olivella biplicala
Prlricola cardiloides
Tapes slaminea
This fauna corresponds to that of the upper San Pedro series, although no
definite relation can be established, owing to the lack of characteristic fossils.
1 A Geological Sketch of San Clemente Island. By W. S. T. Smith. 18th Ann. Kept. D. S. Geol. Sur., Part II., 1S98, p. 492.
= Oil and Gas Yielding Formations of California. By W. L. Watts. Bull. Cal. State Mining Bureau, No. 19, 1900, pp. 61 and 223.
3 Op. cit, p. 233.
ARNOLD — THE PALEONTOLOGY AND STKATIGEAPHY OF SAN PEDRO 57
San Juan Capistrano. — The following fossils were taken from a shallow well at San
Juan Capistrano, in which were also found a tusk and some of the hones of a mastodon:*
Area (cf.) sulicosta Natica ciaiisa Turril.'Ua roopi'ri
Crepidula I'xcavata OstrKi (?) Venericardiabomnlis \^=V. vcntricosal
Nassa mendica Leda ( ?) Vola ( ?)
Dr. Merriam is of the opinion that these fossils are of Pliocene age — an opin-
ion borne out by the similarity of this fauna to that of the Deadraan Island Pliocene.
At Bell Station, on the Los Angeles Terminal Railway in Los Angeles County,
the following fossils were obtained from a well at a depth of between 920
and ],320 feet."
Amiaiitis callosa Mi/uiwl/a (aff.) .^hn/tlcx [^7'crc- (Hivella hfjulira [=0. pcdroafia]
Echiiiarachnius exr.i'nlrirus bra id.] Ktela unduinta
Macoma nasuta Lunatia leirhti Tornaiella ( ?)
This is an upper San Pedro fauna, anil its occurrence at such a great depth
has much significance in showing the great amount of sedimentation that has taken
place in the region between Los Angeles and the ocean since the deposition of the
San Pedro series.
San Diego and Vicinity.^
The Pliocene and Pleistocene deposits of San Diego are similar to those of San
Pedro, and the geologic hi.story of the two regions has been nearly the same.
During the Pliocene epoch the region now occupied by San Diego Bay and vicinity
was a great basin in which coarse gravels and fine sands were depo.sited. The earlier
sediments, which are now exposed along the northern portion of the San Diego mesa,
consist of thick deposits of incoherent coarse gravels, while the later deposits are
made up of plainly bedded yellow sandstones. After the deposition of these layers,
there was an interruption of sedimentation, which was followed during Pleistocene
times by an inundation and deposition of fossiliferous gravels and sands over much of
the San Diego region.
Pacific Beach — Pliocene. — The best exposure of the Pliocene is found at
Pacific Beach, on the coast ten miles north of San Diego. A perpendicular blufi,
varying in height from four feet at Ocean Front to over sixty feet one mile north,
forms the coast line of Pacific Beach. This bluff is composed of brownish yellow
sandstones of Pliocene age, which dip gently toward the south, and disa^ipear succes-
sively beneath the beach as one approaches Ocean Front from the north. The total
thickness of the strata exposed is about two hundred feet. The upper one hundred
feet are fossiliferous, while the lower layers are devoid of fossils. The unfossiliferous
sandstone rests upon coarse incoherent gravels of unknown thickness.
There appear to be two quite distinct horizons in the fossiliferous section of
the Pacific Beach Pliocene. Stratigraphically no distinction can be made, as the
whole series of strata rest conformably upon one another, but faunally there is
1 Op. tit., pp. 59 and 222. 'Op. cit., p 223.
<< The late Tertiary and Pleistocene formations in the vicinity of S.in Diego are mentioned in the following papers:
Distribution of California Tertiary Fo.ssils. By W. H. Ball. Proc. U. S. Nat. Museum, Vol I, 1879, pp. 26-30.
North American Tertiary Horizons. By W. H. Dall. 18th .\na. Rept. U. S. Cleol. Sur., Part II, 1898. p. 335.
Geology of San Diego County; also of portions of Orange and San Bernardino Counties. By H. W. Fairbanks, lltb .\nn. Kept.
Cal, State Mineralogist, 1893, pp. 76-120.
( 8 ) September 27, 1902.
58 CALIFOK'NIA ACADEMY OF SCIENCES.
much difference between the two horizons. The lower fossiliferous strata are distin-
guished by Pecten expansus, Pecten steanisii, Opalia anomala, and Opalia varicostata,
Pecten expansus being very numerous. The upper beds have few Pecten expansus,
but are characterized by Pecten hemphilli, which complete!}' replaces the Pecten
stenrnsii of the lower layers. Echinarachnius excentricus and Crepiduln grnndis are
also conmion in the upper layers.
The series of Pliocene strata exposed at Pacific Beach has been named the
San Diego formation by Dall,' who places it below the Merced formation. At another
place in this paper the writer brings forward reasons for placing the San Diego form-
ation above the Merced. Besides the reasons given at that place (page 17) there
is other evidence showing that the San Diego formation is part of the latest Pliocene.
This is the occurrence in it of Echinarachnius excentricus. This species of echinoderra
is not found in the Merced series or in any of the underlying formations, so far as
known, but is found in the lower San Pedro series (lowest Pleistocene) and in all of the
succeeding formations, and is still living. Considering the short geologic range
usually covered by species of echinoderms, this evidence strongly favors the theory
that the San Diego formation is at the top of the Pliocene, and probably takes in a
part of the lower San Pedro series.
The lithologic and stratigraphic similarity of the San Diego formation to the
Deadman Island Pliocene is marked. Both consist of rather fine, brownish yellow
sand strata only moderately consolidated, except locally, with low dip, and showing
the effect of only a slight movement since their deposition. Both formations are
overlain unconformably by strata of Pleistocene origin. The fannal aspects of the
two formations are somewhat different. Pecten ex'paasus of the San Diego formation
replaces Pecten caurinus, which is abundant in the Pliocene of Deadman Island, and
numerous species are found in the Deadman Island Pliocene which do not occur in
the Pacific Beach Pliocene deposits. Pecten stearnsii is common to both formations,
and as its geologic range is very limited, it is strong evidence of the contemporaneity
of the two formations. Correlating more accurately, the Deadman Island Pliocene
is probably contemporaneous with the lower (Pliocene) horizon at Pacific Beach, for
Pecten stearnsii is limited to that horizon in the San Diego formation, so far as is known.
Pacific Beach — Pleistocene. — The upper six to ten feet of the Pacific Beach
bluff is composed of a gravel and sand formation which rests unconformably upon
the Pliocene strata. The line of demarkation between the Pliocene and the upj)er
Pleistocene formation is generally distinct, as the lower layer of the Pleistocene is of
coarse, fossiliferous gravel, while the underlying Pliocene strata are of fine sand.
Well preserved fossils are found at many points in this Pleistocene layer along Pacific
Beach, while at other places in the same stratum the fossils are so brittle that it is im-
possible to remove them from the soft matrix. The fauna of this Pleistocene stratum
is very similar to that of the upper San Pedro deposits exposed at the north point of
the San Pedro bluff. The break between the faunas of the Pacific Beach Pliocene
and the overlying Pleistocene is much greater than that between the Deadman
Island Pliocene and its overlying Pl'eistocene (lower San Pedro series) layer.
1 North American Tertiary Horizons. By W. H. Dall. 18th Ann. Bept. U. S. Oeol. Sarvey, Part II, 1898, p. 386.
ARNOLD — THE PALEONTOLOGY AND STRATIGKAPHY OF SAN PEDRO. 59
San Diego Mesa — Pliocene. — The San Diego mesa is composed of Pliocene
strata. Outcrops of the soft yellow and brown Pliocene sandstone occur in many
places in the northern part of the city. A good exposure is found at the north end
of Tenth street, a short distance northwest of the Russ school, where a cut on both
sides of a small ravine reveals a section of the Pliocene about fifty feet thick. This
exposure is only about two hundred feet noi'th of the "San Diego well," which was
dug about twenty years ago, and which has become famous through the discussion
of the age of the fossils which were taken from it. Mr. Hemphill, who obtained the
fossils from this well during its excavation, informed the writer that fossiliferous strata
were penetrated to a depth of one hundred and forty-nine feet. As the exposure of
the San Diego formation above the mouth of the well is fifty feet thick, the fossil-
bearing strata of the Pliocene formation of the San Diego mesa are at least two hun-
dred feet in thickness. The dip of the strata above the well is south, or toward the
bay, at an angle of eight or ten degrees.
Twenty-sixth Street — Pleistocene. — A bluff about eighteen feet high rises from
the edge of the bay at the foot of Twenty-sixth street, San Diego, and extends for
two or three blocks both toward the east and toward the west from Twenty-sixth
street, forming the shore line along this part of the bay. At the base of this bluff,
and covered by the water at liigh tide is a stratum six inches thick made up almost
entirely of the upper valves of Anomia limatula. No right valves were found in this
deposit, and this species seemed to be restricted to this layer. A stratum of fine,
yellow fossiliferous sand, four or five feet thick, rests upon the Anomia beds; and
above the fossiliferous bed is about twelve feet of fine brown sand, overlain by sandy
soil. Dosinia poiiderosa, Oallista newcombiana, Mactra californica, and Cardium pro-
ceruin are the predominating species in the yellow sand stratum. The fauna of this
locality is equivalent to that of the upper San Pedro series at San Pedro.
Spanish Bight — Pleistocene. — The Coronado peninsula is a long, low, narrow
sand-spit lying between San Diego Bay and the ocean. Near its western end is a
small inlet on the bay side, known as Spanish Eight. The western shore-line of this
inlet is a bluff' varying in height from twelve to eighteen feet, while the stratum at
the base of the bluff forms the beach, and is covered by the water at high tide. This
lowest layer is composed of a firm, fine brown sand in which are imbedded numerous
large Amiantis callosa, which have the appearance of living shells, so naturally do
they lie on the sand. An attempt to remove them, however, dispels the delusion, for
in most cases they are quite firmly imbedded in the sand layer.
There are three feet of fine, soft, unfossiliferous gray sand above tlie Ainiantis
layer, and this is overlain by a deposit, varying in thickness from three to five feet, of
soft gray sand, which is very fossiliferous near its base and gradually grades into
the almost unfossiliferous gray sand a few feet above. About twelve feet from the
base of the bluff is a layer from three to six inches thick containing numerous Donax
Icevigata cemented together. This Donax layer is the uppermost fossiliferous stratum
the bluff above this being composed of unfossiliferous sands. The fauna of the
Spanish Bight deposits is similar to that of the upper San Pedro series at Los Cerritos,
and the deposits are probably of contemporaneous origin.
60
CALIFOENIA ACADEMY OF SCIENCES.
List of Fossils Collected from the Pliocene and Pleistocene Fokmations of
^ San Diego, California.
Acmtea insessa Hinds
Acmeea pelta Eschscholtz
Actceon Iraskii Stearns
Actaion ( Riclaxis) punc/ocrelala Carpenter
A miantis callona CoNRAU
A mphiasa versicolor Dall
Anomia lamjx' Gray
Anomia liinafula Dall
Astarte branneri, sp. nov
Balanus concavus Bronn
B'Utium aupp.rum Gabb
Bitlium williamsoni , sp. nov
Cadulus nilenlior Carpenter
Cattista newcombiana Gabb
Calliosloma canaliculalum Martyn
CaUiostoma costatum Martyn
CalUostoma gi'mmulatum Carpenter
CaUiostoma tricolor Gabb
Cancer, sp. indet
Cardium procprum Sowerby
Cardium quadrigenarinm Conrad
Cerithidca cali/ornica Haldemann
Chione fluctifraga Sowerby
Chione simillima Sowerby
Chione. succincla Valenciennes
Chlorostoma fuiiehralf A. Adams
Chloroxloma ijallina Forbes
Chlorostoma tnontercyi Kiener
Clidiophora punctata Conrad
Clypide.Ua bimaculata Dall
Columbella ( Msopiis) chrysalloidea Carpenter
Columhella ( Astyria) ijausapata Gould
Coluinbella (Astyris) gausapata var. carinata Hinds.
Columbella ( Aslyris) tuberosa Carpenter
Conns cnli/oriiicus Hinds
Pleistocene.
O Vi
X
X
X
X
X
X
X
X
X
X
X
an
X
X
X
X
X
X
X
X
X
10 •=
(1<B
X
X
X
X
X
X
X
X
ARNOLD — THE PALEONTOLOGY AND STKATIGKAPHY OF SAN PEDRO.
61
Cooperdla subdiaphana Carpenter
Corbula lute.ola Carpen'ter
Crepidula adunca Sowerby
Crepidula grandk Middendorf
Crepidula onyx Sowerby
Crucibulum spinosum Sowerby
Cryplomya califoraira Conrad
Cylichna alba Brown
Delphinoidea coronadoennis, sp. nov
Dentalium hexarjoiium Sowerby
Denlalium pseudohexagoniim Dall
Diplodonta orbella Gould
Diplodonta srrricata Reeve
Donax Imvir/ata Deshayes
Dosinia pondi'rosa Gray
Drillia canrellata Carpenter
Drillia hemphilli Stearns
Drillia incisa Carpenter
Drillia inermis Hinds
Drillia inermis var. penicillata Carpenter .
Echinarachnius excentricus Eschscholtz.. .
Eulima hastala Sowerby
Mulitna micans Carpenter
Eupleura muriciformis Broderip
Fissurella volcano Reeve ,
Olycymeris barbarensis Conrad
Haliotis falgens Philipp i
Hipponyx cranioides Carpenter
Hipponyx lumens Carpenter
Kellia laperousii Deshayes
Lmvicardium subsirialum Conrad
Lacuna compacta Carpenter
Lacuna solidula (Loven) Carpenter
Lamellaria slearnsii Dall
Leda hamata Carpenter
Leda taphria Dall
Littorina scutulata Gould
Lucina aculilineata Conrad
Pleistocene.
O V
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
«■=
X
X
X
X
X
X
X
X
X
X
X
(UK
62
CALIFORNIA ACADEMY OF SCIENCES.
Lucina californka Conrad
Lue.ina nuttalli Conrad
Lucina Unnisculpla Carpenter
Macoma imlentata Carpenter
Macoma inrjuinala Deshayes
Maeoma nasnta Conrad
Macoma namila var. keheyl Dall
Macoma xecla Conrad
Macoma yoldiformis Carpenter
Mactra cali/ormra Conrad
Mactra (Spixula) catilliformin Conrad
Mactra cxoleta Gray
Mactra (Spixvia) falrala Godld
Manii'iUn unijulala Carpenter
Mantjilia /tlriona C. B. Adams
Melampus olivareun Carpenter
Metis alia Conrad
Modiola recta Conrad
Monoceron enrjonatum Conrad
Murcx ( Ptrrohytis) nul.lalli Conrad
NoHSa californiana Conrad
Nasaa ccrritennis, sp. nov
Nassa/onxata Gould
Nassa mcndirn Gould
Nassa inrndica var. rooperi FoRBE.s
NanKa pcrpini/uit: Hinds
Nassa teyula Reeve
Neverita recluziana Petit
Norrinia norrinii Sower by
Nucula supraxlriata Carpenter
Ociiiebra interfoxsa Carpenter
Ocinchra /uridn Middendorf
Ocinchra pouhoni Nuttall
Ocini'bra perita Hinds
Odostomia nuciformis var. avellana Carpenter
Odoslomia tenuis Carpenter
Olivella biplicata Sowerby
OUvella intorta Carpentee
Pleistocene.
X
X
X
X
X
X
X
X
X
X
X
(J a
CO
X
X
X
X
X X
X
X
X X
i
X X
■^ I
X I X
X
X
X
X
X
X
X
X
X
X
X
X
X
u m
X
X
ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO.
63
Pleistocene.
1
Pliocene.
S.5P
(J rt
CO 04
a n
PhP3
X O
Otivellct pedrocnift Conrad .
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Ostrca liirida Carpenter
Oslrea vcatchi { ? ) Ga bb
X
Pecti'n cxpuiisHs Dall.
Fecial haMatus Sowerby
Pe.cten hemphilH Dall
X
Pr.ctfn hericeux Gould
Pecien laliauritus Conrad
Pecten latiaurilus var. monotimrrh Conrad
Pecten subvenirkoKus Dall
Periploma argeniaria Conrad
X
X
1
X
Phasianella compla Gould
1
Plcuroloma carpenteriann Gaee
X
Pomaulax undosus Wood
X
X
X
X
Purpura crispala Chemnitz
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Saxidomus aralus Gould
Scala lincta Carpenter
X
Semele pulchra Sowerby
Siliqtin lucidn Conra d
Silitjiia palula var. nutlnlli Conrad
Siphonalia keUettii Forbes
Slrongylocentrotus purpnratus
Tapes sCaminea Conrad
X
64
CALIFORNIA ACADEMY OF SCIENCES.
Tapes lenerrima Carpenter
Te.Uina hodeijensU Hinds
Terebra simplex Carpenter
Tivi'la crnssnlelloides Conrad
Tornalina cerealis Gould
Tornalina cukilelln Gould
Tornalina hnrpa Dall
Trtsus nuUalli Conrad
Turriti'Ua rooperi Carpkntkr
Turbonilla (four species)
Vilrinella, sp. iudet
Vnu'ricardia ven/ricosa { ? ) Gould
Voloarina ttnrla Sowerby
Volvula cylindrica Carpenter
Yoldia coopcri Gabe
Pleistocene.
X
.X
X
X
X
X
X
X
X
X
X
X
PhP3
u cd
Chapter III
FAUNAL RELATIONS.
1 . Pliocene.
The fauna of the Deadman Island Pliocene strata is somewhat similar to the
fauna which is now living in the waters only a short distance oflshore from San
Pedro. Dredging' has shown this, and has also shown that the sediments now being
deposited off San Pedro are similar to those which make the strata of the Deadman
Island and Timm's Point Pliocene. The Pliocene strata consist for the most part of
rather fine clayey brown sand which has its counterpart in the fine sand and mud
now being deposited off shore from San Pedro. The Pliocene fauna, although quite
similar to the fauna now living off San Pedro, still has many species which are found
living only north of that place. To state it more precisely, 18.5 per cent, of the
species found in the Deadman Island Pliocene fauna are found living now only to
the north of San Pedro. Many of these northern species are limited in range to the
boreal waters north of the Puget Sound district. The occurrence in large
numbers in the Deadman Island Pliocene of Pecten caurinuii, Fanomya ampla,
Thyatiira hixect<i, Pecten hericeut<, Lucimi acuiilineata, Natica clauna, several species
of 2ropho7i, and other boreal and subboreal forms, leads to the conclusion that the
strata in which they occur were deposited in water probably much colder than that
which is found offshore from San Pedro at the present time. The species found fossil
in the Deadman Island Pliocene, and still living at San Pedro, also offer evidence
of the northern climatic conditions during later Pliocene times. Of the species
living at San Pedro at the present time, and found fossil in the Pliocene, nearly all
are more common toward the north. In fact, San Pedro is the southern limit of the
known range of many of the species. Boreal or subboreal conditions so near the
shore imply more or less similar climatic conditions on the land, at least near the
ocean. This being the case, it is more than probable that during the latter part of
the Pliocene epoch the climate was much colder on the coast of Southern California
than it is at the present time.
^ During the summer of 1901 dredging was carried on in the waters adjacent to San Pedro, Catalina Island, and San Diego, by a
party of zoologists under the supervision of Dr. W. E. Ritter, of the University of California. The information obtained by the party was
very important, and that regarding the mollusca was especially so to the conchologists and paleontologists of this coast, as it extended the
known southern range of many species heretofore known only north of San Pedro. To Professor Raymond, who had charge of the molUisca
obtained, and to Mrs. Oldroyd, who assisted in the classification of the same, the writer is indebted for much of the information regarding
the offshore fauna near San Pedro.
( 9 ) [65] June 10, 1903.
66 california academy of sciences.
2. Pleistocene.
The Lower San Pedro Series. — The lower San Pedro strata of Deadman
Island and the San Pedro bluffs were dejiosited in water shallower than that in which
most of the underlying Pliocene strata were laid down. The sediments and fauna of
the lower San Pedro deposits show this. The sediments consist for the most part of
medium grained gray sands such as are being deposited at the present time in about
ten to twenty fathoms of water off the San Pedro shore-line. The occurrence in the
lower San Pedro deposits of many species which live only between tides also oflfers
evidence of their close in-shore deposition. The fauna of the lower San Pedro series
is one of transition between the boreal or subboreal fauna of the later Pliocene and
the semitropical fauna of the upper San Pedro series. Two causes account for this.
First, the deposits being laid down in shallower water than that in which the Pliocene
sediments were deposited would necessarily contain fewer of the colder, deeper water
forms of the Pliocene; and second, the cold climatic conditions prevalent during the
later Pliocene epoch were giving place to a warmer climate, which had its effect
upon the boreal species which inhabited the water off San Pedro during Pliocene times.
The species found in the lower San Pedro deposits and now found living only
north of San Pedro comprise 17.4 per cent, of the lower San Pedro fauna. This
percentage is only a little lower than that of the northern species found in the Plio-
cene (the latter being 18.5 per cent.), and shows, considering the fact that the lower
San Pedro beds were deposited in shallower water than that in which the Pliocene
was laid down, that the climatic conditions had changed but little during the period
intervening between the deposition of the Pliocene and lower San Pedro series. The
evidence offered by several species (3.4 per cent, of the entire lower San Pedro
fauna) which are found in the lower San Pedro series, but are now found living only
south of San Pedi-o, shows, however, that the conditions of temperature were changing.
Besides the distinctly northern forms which either disappear or become scarce
in the period between the Pliocene and lower San Pedro series, there are many
species best suited for northern conditions which become rare in the lower San Pedro
series, while species best suited for southern conditions begin to increase in num-
bers. All of the evidence shows that climatic conditions were changing from boreal
towards tropical during the time of the deposition of the lower San Pedro series.
That the boreal conditions still preponderated during this period, however, is shown
by the fauna of the lower San Pedro.
The Upper San Pedro Series. — The deposits of the upper San Pedro series
consist of coarse gravels, and sands which show alternating dune and water bedding;
and the rapidly changing conditions under which the deposits were laid down is evi-
denced by their variation. The fauna of the upper San Pedro series is southern in
character, and, as would be exi^ected, approaches more nearly the present living
fauna of the San Pedro region. Being deposited in shallower water tlian either the
Pliocene or lower San Pedro deposits, one would expect it to contain fewer of the
cold water species and more of the species found only between tides and in the warm
ARNOLD — THE PALEONTOLOGY AND STEATIGKAPHY OF SAN PEDEO. 67
waters of the lagoons. Such is the case, but it is a noticeable fact that in the upper
San Pedro fauna 14.2 per cent, are species which are found living at the present time
only south of San Pedro. Not only is this true, but of the species in the upper San
Pedro fauna which are now living at San Pedro a lai'ge number are best suited for
southern conditions.
Although 6.1 per cent, of the upper San Pedro fauna ai'e found now living
only north of San Pedro, these northern species are only very rarely found in the
upper San Pedro deposits. On the other hand, not only are most of the southern
forms common in the upper San Pedro series, but the whole fauna has a semitropical
aspect. Such sp)ecies as Cardium elatum, Area lahiata, Peden dentatus, Mactra
exoleta, Venus giiidia, Murex keanus, Eiqjleura muriciformis., Cancellaria tritonidea,
and Bulla jmnctalata give this fauna its tropical character. The evidence offered by
the southern forms outweighs the evidence of the northern species in another respect,
for it would require a great change in climate from the conditions prevalent during
later Pliocene times to cause these southern sjiecies to migrate northward to the San
Pedro region; while this same change in climate would not so visibly affect the
northern species, for they could simply migrate into deep water, where the conditions
would more nearly approximate the boreal. This latter has been the case with such
species as Lucina acutilineata, Chrysodomus tabulatus, Solariella cidaris and Solnriella
peramabilis, which now inhabit northern waters, near shore, but which have been
dredged in the deep water between Catalina Island and the mainland.
The evidence offered by the upper San Pedro fauna leads to the conclusion
that semitropical conditions prevailed during the deposition of this formation.
The similarity of the fauna of these beds with that now living at San Pedro and the
adjacent coast makes it probable that the conditions, although more tropical than those
of the present time, were not extremely tropical.
3. Relation of the Late Pliocene, Pleistocene, and Living Faunas of
California to the Fauna of Japan.
Great similarity exists between the late Tertiary and Pleistocene marine in-
vertebrate fauna of Japan and that of the western coast of the United States. This
similai'ity is shown by a comparison of the species found in the uppermost Tertiary
deposits in the region about Tokio and the species found in beds of similar age along
the Pacific coast of North America.
Dr. Brauns' has described some of the formations in the vicinity of Tokio, and
has given lists and descriptions of the fossils found in these formations. Dr. Brauns
thinks that the deposits he has examined are of the uppermost Tertiary. His lists of
fossils lead to that conclusion, if one compares them with the fauna of the later Plio-
cene of California. Many of the Japanese species have counterparts in species found
in the San Pedro deposits. Such species, for example, as Lucina borealls, Cylichna
cylindracea, and Fecten yessoensis are closely related, if not identical, with the west
1 Geology of the Environs of Tokio. By David Brauns. Mem. Sci. Dept. Univ. of Tokio, No. 4, 1881, pp. 27, 61.
68 CALIFORNIA ACADEMY OF SCIENCES.
American species, Lucina acutilineata, Cylichna alba, and Pecten caurinus. There
are many such cases of the similarity of species, and in a few instances identical
species have been found which are common to the two regions. The following species
are found in Dr. Brauns' list of upper Tertiary fossils from Ojai, near Tokio, which
are also found in the San Pedro deposits:
List of Fossils from Ojai, which are Found in the San Pedro Deposits.
Cardium cnli/orniense[= C. forhis] Kellia suborbiculnris Panopea gencrosa
CrepkliUa acuhata Macomn nasuta Tresvs nullalll
Among the species now found living in Japan, and on the west American
coast, and also found in the San Pedro deposits, are the following:'
List of Living Species Common to Japan and the West Coast of North America,
which are Found in the San Pedro Deposits.
Cardium corbis Macoma nasula Sawjuinolaria nullalU
Crepidula grandis Macoma secta Siphonalia kellellii
CryptochHon siclleri Mytilus eduUs Tresus nultalU
Dentalium hexagonum Natica clausa Tapes staminea
Drillia inermis Pectan hericens Tellina bodegennis
Leploihyra carpenleri Purpura crispata Tritonium ( =^ Prkne) oregonrnais
Macoma edulis Panopea generosa Trophon orpkeus (^ T.sluarti{'>))
Macoma inquinata Pododesmus macroschism.a
The living faunas of the Japanese and west American coasts, though having
many species in common, are not as closely related as are the upper Tertiary and
Pleistocene faunas of the same regions. This has been brought about in two ways.
First, the more or less close connection between the two regions, which existed in
late Tertiary and early Pleistocene times, has been broken; and second, southern
species from the warm China seas have migrated northward and mingled with the
Japanese early Pleistocene species, while Panama species have come northward
during the upper San Pedro time and changed the aspect of the fauna of the west coast
of North America. Those species which Japan and the west coast of North America
have in common are either circumboreal or are forms which have changed little since
the habitats of the two faunas were similar and connected; those species which differ
but slightly have in many cases made this change since the connection was broken;
and many of the forms which occur in each fauna, and which have no counterpart in
the other, have come into these faunas in comparatively recent times.
An interesting example of the migration which took place between Japan and
western North America is offered by the genus Halioth. This genus is of Asiatic
origin, but it migrated to the northern American coast during late Pliocene or early
Pleistocene times. This is shown by the absence of this species from any of the pre-
Pleistocene formations along this coast. Only two fossil Haliotidm have been found
on this coast, one being taken from the upper San Pedro (Pleistocene) gravel of
^ TblB liBt Is compiled from the foUowiDg papers:
Mollusks of Western North America. By P. P. Carpenter. Smithsonian Miscellaneous Collections, No. 252, 1872.
Catalogue of California Fossils. By J. G. Cooper. 7th Ann. Kept. Cal. State Mineralogist, 1888.
AENOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 69
Deadrnan Island, and the other from the Pleistocene (upper San Pedro series) at
Spanish Bight, San Diego. The nearly total absence of this species from even the
Pleistocene deposits is accounted for by the length of time it would take the species
to migrate to the California coast from Alaskan waters, where it first reached the
American shore during Pliocene or early Pleistocene times. This scarcity of the
Haliotidce, which are so common in the living fauna, in even the upper San Pedro
deposits, is more evidence in favor of the theory that a long period of time has elapsed
since the dejiosition of the upper San Pedro series.
Dr. J. P. Smith explains the phenomena of the similarity of the late Tertiary
and early Pleistocene fauna, and the somewhat similar, though diverging, living faunas
in this way: during Tertiary time there was an elevation of the submarine shelf
which follows the line of the Aleutian Islands. This elevation made possible the
intermigration of many species which oiherwise never could have crossed the abyssal
gap which now separates the northwestern American and Japanese regions. After
the elevation of this shelf it remained in a more or less constant position for some
time, and then became deeply submerged again, with a consequent breaking of the
faunal connection between the two regions.
From the evidence brought forward in this paper, it has been seen that the
late Pliocene and early Pleistocene was a period of the southward extension of boreal
conditions on the west American coast; it would, therefore, be natural to infer that
approximately the same conditions prevalent on the Californian coast during late
Pliocene times also prevailed along the Japanese coasts during the same period. A
detailed study of the Tertiary and Pleistocene deposits of Japan is awaited with
interest, as such a study will throw more light on the conditions prevailing on the
shores of the North Pacific during the later geologic epochs.
Part II. Descriptions of Species
THE PLIOCENE AND PLEISTOCENE FAUNA OF SAN PEDRO
AND VICINITY.
Synopsis.
Page
CCELENTER ATA 86
CL.\SS I. ANTHOZOA 86
Family I . Txirhinolidoi 86
Genus Caryophj'llia 86
1. arnoldi Vaughan 86
2. pedroeusis v., sp. iiov 87
3. califoruica V., sp. uov 87
Genxis Paraoyathua Milne-Edwards & Haimf 88
4. pedroeusis V., sp. uov 88
ECHINODERMATA 90
CLASS II. ECHINOIDEA 90
SUBCLASS EUECHINOIDEA 90
Order Diadematoida 90
SOBORDER StEREOSOMATA 90 .
Family II. Echinomelridie 90
Geaus Strougyloceutrotus Brandt 90
5. francisoauus A. Agassiz 90
6. piirpuiatus Stimp-son 90
Order Cltpeastroida 91
Family III. Scutellidce 91
Genus Scutella Lamarck 91
Subgenus Ecbinarachnius Leske 91
7. (E.) excentricus Esch.scholtz 91
MOLLUSCOI DE A 92
CLASS III. BKYOZOA 92
8. Sp. iudet 92
CLASS IV. BRACHIOPODA 92
Order Arthropomata 92
Family I V . Tercbraliilida: 92
Genus Teiebratalia Beecher 92
[S. B.] hemphilli Dall 92
9. sniithi, sp. nov 93
Geuus Laqueiis Dall 93
10. Jeffreys! Dall 93
Family V. Lingulidte 94
Subfamily Lin;/ulince 94
Genus Glottidia Dall 94
[S. B.] albida Hinds 94
(71 )
72 CALIFORNIA ACADEMY OF SCIENCES.
MOLLUSCA 95
CLASS V. PELECYPODA 95
Order Prionodesmacea 95
SUPERFAMILY NUCULACEA 95
Family VI. NuculUlce 95
Genus Nucula Lamarck 95
Subgenus Acila H. & A. Adams 95
11. (A.) caslrensis Hinds 95
Subgenus Nucula, s. s 96
12. (N.) suprastriata Carpenter 96
Famibj Via. Ledidm 96
Genus Leda ScHnMACHER 96
13. fossa Baird 96
14. hamata Carpenter 97
15. minuta Fabr., var. prascursor, var. nov 97
16. taphriaDALL 98
Genus Yoldia MIjller 99
17. cooperi Gabb 99
IS. scissurata Dall 99
SUPERFAMILY ARCACEA 100
Family VII. Arcidce 100
Subfamily Pectunculince '00
Genus Glycymeris Da Costa 100
19. barbarensis Conrad 100
20. septentrionalis Middendorf 101
Suhfamily Arciiice 101
Genus Area (Linne) Lamarck 101
21. labiata SowERBY 101
SUPERFAMILY OSTRACEA 10^
Family VIII. Oslreidce 102
Genus Ostrea (Linne) La m arck 102
22. luiida Carpenter 102
SUPERFAMILY PECTINACEA 103
Family IX. Peclinidoi 103
Genus Peeten Muller 103
Subgenus Pecteu, s. s 103
[S. B.] (P.) bellus Conrad 103
23. (P.) dentatus Sowerbv 104
[S. D.] (P.) hemphilli Dall 105
24. (P.) stearnsii Dall 106
Subgenus Chlamys Bolten 107
Section Patinopecteii Dall 107
25. (P.) cauiinus Godld 107
[8. D.] (P.) expausus Dall 108
Section Nodipecten Dall 108
26. (N.) subuodosus Sowerby 108
Section Chlamys, s. s 109
27. (C.) hastatus Sowerby 109
28. (C.) hericeus GooLD 110
29. (C.) hericeus var. strategus Dall HO
30. (C.) jordaui, sp. nov HI
31. (C.) latiauritus Conrad HI
32. (C.) latiauritus CoNR., var. fragilis, var. nov 112
33. (C.) latiauritus Conr., var. monotimeris Conrad 112
[S. D.] (C.) opuntia Dall 113
Section Plagiocteuium Dall 113
34. (P.) uewsomi, sp. nov 113
[S. D.] (P.) subveutricosus Dall 114
35. (P.) veutricosus Sowerby 114
Subgenus Hiuuitea De France 115
36. (H.) giganteus Gray 115
ARNOLD — THE PALEONTOLOGY AND STEATIGRAPHY OF SAN PEDRO. 73
MOLLUSCA (Continued.)
Family X. Limidce 115
Genus Lima (Bruguiere) Cuvier 115
Subgenus Lima, «. s 115
Section Mantelhim Ad.^m.s 115
37. (M.) dehiseens Cone.4d 116
SUPERFAillLY ANOMIACEA 116
Family XI. Anomiidce 116
Genus Pododesmns Philippi 116
Section Mouia Gr.w 116
38. (M.) macroschisma Deshates 116
Genus Anomia LiNXE 117
39. lampe Gray 117
[S. D.] limatula Dall 118
SUPERFAMIL Y MYTILACEA 118
Family XII. Mytilida: 118
Genus Mytilus (Linne) Bolten 118
Section Mytilus, a. s 118
40. (M.) edulis Linn^ 118
Geuus Septifer Eecluz 119
41. bifurcatus Reeve 119
Genus Modiolus Lamarck 120
Section Modiolus, s. s 120
42. (M.) foruieatus Carpenter 120
43. (M.) rectus Conrad 120
Genus Lithoi^haga Bolten 121
44. plumula Hanlev 121
Order Axomalodesmacea 121
SUPERFAMILY ANA TINACEA 121
Famil;/ XIII. Periplomidce *. 121
Geuus Periploma Schumacher 121
45. argentaria Conrad 121
Family XI V. Thrariidm 122
Geuus Thracia (Leach) Blainvillb 122
46. trapezoides Conrad 122
Family X V. Pandoridce 123
Genus Pandora 123
Subgenus Keunerlia Carpenter 123
47. (K.) bicariuata Carpenter 123
48. (K.) filosa Carpenter 124
Geuus Clidiophora Carpenter 124
49. punctata Conrad 124
Family X VI. Lyonaiidie 125
Geuus Lyonsia TuRTON 125
50. californica Conrad. 125
Gemis Mytilimeria Conrad 125
51. nuttalli Conrad 126
SUPERFAMILY POROMYACEA 126
Family X VII. Verlicordiidie 126
Genus Verticordia S. Wood 126
52. noyemcostata Adams & Reeve 126
Order Teleodesmacea 127
SUPERFAMIL Y ASTARTACEA 127
Family X VIII. Aslartidw 127
Genus Astarte Sowerby 127
Subgenus Crassinella Bayle 127
53. (C.) brauneri, sp. nov 127
SUPERFAMILY CARDITACEA 128
Family XIX. Cardiiidai 128
( 11) ) June 11, 1903.
74 CALIFORNIA ACADEMY OF SCIENCES.
MOLLUSC A (Continued).
Genus Venericardia Lamakck 128
54. barbareusis Stearns 128
55. veutricosa Gould 128
Genus Lazaria Conrad 129
56. Bubquadrata Carpenter 129
SUPEBFAMILY CHAMACEA 130
Family XX. Chamidce 130
Genus Chama (Pliny) Linne 130
57. exogyra Conrad 130
58. pellucida Sowerby 130
SUPERFAMILY LUCINACEA 131
Family XXI. Lucinidie 131
Genus Lucina Brcgdiere 131
59. acutilineata Conrad 131
60. califoruica Conrad 132
61. nuUalli Conrad 132
62. tenuisculpta Carpenter 133
Family XXI I. Diplodonlidce 133
Genus Diplodouta 133
Section Diplodouta, s. s 133
63. (D.) orbella GooLD 134
64. (D.) serricata Eeeve 134
Family XXIII. Cryptodontidas 135
Genus Thyasira Leach 135
65. bisecta Conrad 135
66. gouldi Philippi 135
SUPERFAMILY LEPTONACEA 136
Family XXI V. Leptovidu; 136
• Genus Bornia Philippi 136
67. retifera Dall 136
Genus Kellia Tprton 136
Section Kellia Turton, s. s 136
68. (K.) laperousii Desha yes 137
69. (K.) suborbicularis Montagu 137
Family XX I'. KellidUdm 138
Genus Aligena H. C. Lea 138
70. cerritensis, sp. nov 138
SUPERFAMILY CARDIACEA 138
Family XX VI. Cardiidce 1 38
Genus Cardium (Linne) Lamarck 138
Subgenus Trachy cardium Morch 138
71. (T.) quadrigenarium CoNEAD 139
Subgenus Eiugicardium Fischer 139
72. (E.) procerum Sowerby 139
Subgenus Cerastoderma Morch 140
73. (C.) coibis Martyn 140
Subgenus LsBvicardium Swainson 140
74. (L.) elatum Sowerby 141
75. (L.) substriatum Conrad 141
Genus Protocardia Beyrich 142
76. centifilosa Carpenter 142
SUPERFAMILY VENERACEA 142
Family XX VII. Veneridce 142
Subfamily Venerince 142
Genus Tivela Link 142
77. crassatelloides Conrad 143
Genus Callista PoLi 143
78. newcombiana Gabb 143
79. subdiaphana Carpenter 144
80. subdiaphana Carpenter, var. pedroana, var. nov 144
AENOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 75
MOLLUSCA (Continued).
Subgenus Amiantis Conrad 145
81. (A.) callosa Conrad 145
Subfamily Dosinince 146
Geuus Dosinia Scopoli 146
[S. D.] ponderosa Gray 146
Genus Venus Linne 146
[S. B.] perlamiuosa Conrad 146
Subgenus Chioue Megerle 147
82. (C.) fluctifraga SowERBY 147
83. (C. ) gnidia Sowerby 147
84. (C.) neglecta Sowerby 148
85. (C.) simillima Sowerby 148
86. (C.) succincta Valenciennes 149
Subfamily Tapetin<^ 149
Genus Tapes Megerle 149
87. lacineata Carpenter 150
88. staminea Conrad 150
89. teuerrima Carpenter 151
Genus Saxidomns Conrad 151
90. arat us Gould 151
Subfamily Gemminm 152
Genus Psephis Carpenter 152
91 . salmonea Carpenter 152
92. tautilla Gould 153
Family XX VIII. Cooperellidce 153
Geuus Cooperella Carpenter 153
93. subdiaphana Carpenter 153
Family XXIX. Petricolidai 154
Genus Petricola Lamarck 154
Section Petricola Lamarck, s. s 154
94. (P.) carditoides Conrad 154
Section Rupellaria Fledrian 155
95. (R.) lamellifera Conrad 155
Section Petrioolaria 155
96. (P.) denticulata Sowerby 155
97. (P.) cognata C. B. Adams 156
SUPERFAMILY TELLINACEA 156
Family XXX. Tellinidce 156
Geuus Tellina Linn^ 156
Subgenus Moerella Fischer 156
98. (M.) salmonea Carpenter 157
Subgenus Angulus Megerle 157
99. (A.) buttoni Dall 157
100. (A.) bodegeusis Hinds 158
101. (A.)id£eDALL 158
102. (A.) rubescens Hanlet 159
Geuus Metis H. & A. Adams 160
103. alta Conrad 160
Genus Macoma Leach 160
Subgenus Macoma, s. s 161
104. (M.) calcarea Gmelin 161
105. (M.) indentata Carpenter 161
106. (M.) inquiuata Deshayes 162
107. (M. ) nasuta Conrad 163
108. (M.) nasuta Conrad, var. kelseyi Dall 164
109. (M.) seota Conrad 164
110. (M.) yoldiformis Carpenter 165
Family XXXI. Semelida Schumacher 165
76 CALIFOENIA ACADEMY OF SCIENCES.
MOLLUSCA (Continued).
Genus Semele 165
111. decisa CoNR.\D 165
1 12. pulchra Sowerey 166
113. pulchra Sowerey, var. mouteieyi, var. uov 166
Genus Cumiugia Sowerey 167
1 14. californica Conrad 167
Family XXXII. Psatnmohiidie.. . . 167
GeuTis Psammobia (L.\marck) Bowmen 167
Subgenus Psammobia, s. s 167
115. (P.) eilentula Gabb 168
Genus Sanguinolaria Lamarck 168
Section Nuttallia Dall 168
116. (N.) nuttalli Conrad 168
Genus Tagelus Gray 169
117. californianus Co.nrad 169
Family XXX I II . Donacidm 169
Genus Donax (Linne) Lamarck 169
1 18. californica Conrad 170
1 19. l^vigata Deshayes 170
SUPERFAMIL Y SOLENACEA 171
Family XXXIV. Solenidce 171
Genus Solen Linne 171
120. rosaceus Carpenter 171
121. sicarius Gooi.D 172
Genus Siliqua Megerle 172
122. lucida Conrad 172
123. patula Dixon, var. nuttalli Conrad 173
SUPERFAMILY MACTRACEA 174
Family XXX V. Maclridai 174
Subfamily Mactrinte 174
Genus Mactra Linne 174
124. californica Conrad 174
125. exoleta Gray 175
126. hempbilli Dall 175
Subgenus Spisula Gray 175
127. (S.) catilliformis Conrad 176
128. (S.) falcata Gould 176
Subfamily Pieropsidince 177
Genus Labiosa (Schmidt) Moller . . 177
Subgenus Rseta Gray 177
129. (R.) uudulata Gould 177
Subfamily Lulrariiiiat 178
Genus Tresus Gray 178
130. nuttalli Conrad 178
SUPERFAMILY MYACEA 179
Family XXX VI. Myacidce 179
Genus Platyodon Conrad 179
131. cancellatus Conrad 179
Genus Cryptomya Conrad 179
132. californica Conrad 180
Fainily XXX VII. Corhulidie 180
Genus Corbula (BROoniiiRE) Lamarck 180
133. hitcola Carpenter 181
Genus Nesera Gray 181
134. pectinata Carpenter 181
Family XXX VIII. Saxicavidw. 182
Genus Panopea Menard 182
135. generosa Goold 182
ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OP SAN PEDRO. 77
MOLLUSCA (Continued).
Genus Pauomya Gray 183
136. ampla Dai.l 183
SUPERFAMILY ADESMACEA 183
Family XXXIX. Pholadldte 183
Subfamily Pholatlinae 183
Genus Zirphaja Leach 183
137. gabbii Tryon 184
Subfamily Jouanni'tinii- 18*
Geuus Pboladidea Goodall 184
Subgenus Pboladidea, s. » 184
Section Peuitella Valenciennes 184
13S. (P.) penita Conrad 184
CLASS VL SCAPHOPODA 185
Order Solenoconchia 185
Family XL. Dcnlaliida: 185
Genus Deutalium Linne 185
139. hexagonum Sowerby 185
140. iudiauorum Carpenter 186
141. pseudobexagouum Dall 186
142. semipolitum Broderip & Sowekby 187
Genus Cadulns Philippi 187
143. nitentior Carpenter 187
CLASS VII. GASTROPODA 188
Order Opisthoeranciiiata 188
Family XLI . Actaoiiidce 188
Geuus Actteou Montfort ._ 188
144. traskii Stearns 188
Subgenus Riclaxis Dall 188
145. (R.) punctocoelata Carpenter 189
Family XLI/. Tornatinidie 189
Genus Tornatina A. Adams 189
146. cerealis Gould 189
147. culcitella Gould 190
148. eximia Baird 190
149. barpa Dall 191
Genus Volvula A. Adams 191
150. eylindrica Carpenter 191
Family XLI II . Scaphandridce 192
Genus Cylicbna Loven 192
151. alba Brown 192
Family XLI V. Bullidm 193
Genus Bulla Linne 193
152. punctulata A. Adams 193
153. quoyl Gray 193
Genus Haminea Leach 194
154. virescens Sowerby 1 94
Order Pulmonata 194
Suborder Stylo mmatophora 194
SUPERFAMILY MONOTREMATA 194
Family XL V. Helicidm 194
Genus Helix Linne 194
Subgenus Epiphragmophora Strobel 194
155. (E.) sp. indet 195
SUPERFAMILY HYGROPHILA 195
Family XL VI. Limnoiidce 195
Subfamily Planorbince 195
Geuus Planoibis Guettard 195
156. tumidus Pfeiffer 195
157. vermiculaiis Gould 195
78 CALIFORNIA ACADEMY OF SCIENCES.
MOLLUSCA (Continued).
Family XL VII. Physkhe 196
Genus Physa Dkaparnauu 19(i
158. heterostropha Say 196
SUPERFAMIL Y DITREMA TA 196
Family XL VIII. Auriculida 196
Subfamily Melampince 196
Gemis Melampiis Montfort 196
159. olivaceus Carpenter 197
SUPERFAMILY PETROPHILA 197
Family XLIX. Gadiniidce 197
Genus Gadiuia Gray 197
160. reticulata Sowkrby 197
SuPEROKDER StREPTONEURA 198
Order Ctenobranchiata 198
SUPERFAMILY TOXOGLOSSA 198
Family L. Terebridre 198
Genus Terebra Bruguiere 198
Section Acus (Humphrey) Gray 198
161. (A.) simplex Carpenter 198
Family LI. Conidce 199
Genus Conus Linne 199
162. ealifornicus Hinds 199
Family LI I. Pleu rotomidte 1 99
Genus Pleurotoma Lamarck 199
163. perversa Gabb 200
Subgenus Borsonia Bellardi 200
164. (B.) bartschi, sp. uov 200
165. (B.) dalli, sp. nov 201
166. (B.) booveri, sp. nov 201
Subgenus Leucosyriux Dall 202
167. (L.) pedroaua, sp. nov 202
Subgenus Geuota Adams 202
Section Dolichotoma Bellardi 202
168. (D.) carpenteriaua Gabb 202
169. (D.) cooperi, sp. nov 203
170. (D.) tryoniana Gabb 203
GenusDrillia Gray 204
171. cancellata Carpenter 204
172. hemphilli Stearns 204
[S. D.] incisa Carpenter 205
173. inermis Hinds 205
174. inermis, var. penicillata Carpenter 205
175. johnsoni, sp. nov 206
176. merriami, sp. nov 207
177. montereyensis Stearns 207
178. pudica Hinds 208
179. renaudi, sp. nov 208
180. torosa Carpenter 209
Genus Bela Gray 209
181. fidicula Gould 209
182. sanctfe-moniciB, sp. nov 210
Genus Mangilia (Leach) Kisso 210
Subgenus Clatburella Carpenter 210
183. (C.) couradiana Gabb 210
Subgenus Cytbara Schumacher 211
184. (C.) branueri, sp. uov 211
Subgenus Mangilia Ris.so, s. s 211
185. (M.) augulata Carpenter 212
186. (M.) hooveri, sp. nov 212
ARNOLD — THE PALEONTOLOGY AND STRATIGKAPHY OF SAN PEDRO. 79
MOLLUSCA (Continued).
187. (M.) iuteifossa var. pedroana, var. uot 213
188. (M.) interlirata Stearns 213
189. (M.) oldroydi, sp. uov 213
190. (M.) painei, sp. uov 214
191. (M.) sculpturata D.4LL 214
192. (M.) striosa 0. B. Adams 215
Subgenus Tarauis Jeffreys 215
193. (T.) strongi, sp. iiov 215
Subgenus Siiirotropsis Sars 216
194. (S.) Pleurotoma smithi, sp. uov 216
Family Lll I . CanceUarud(e 217
Geuus Caucellaria Lamarck 217
Subgenus Cancellaria, s. s 217
195. (C.) cooperi Gabb 217
196. (C.) orawfordiana Dall 217
197. (C.) tritonidea Gabb 218
Genus Admete Moller 219
198. gracilior Carpenter 219
Family LI V. Olividce 219
Genus Olivella Swainson 219
199. biplicata Sowerby 219
200. iutorta Carpenter 220
201. pedroana Conrad 221
Family L V. MargincUidce 221
Geuus Margiuella Lamarck 221
202. jewettii Carpenter 221
Section Vol variua Hinds 222
203. (V.) varia Sowerby 222
Family L VI. Mitridte 222
Geuus Mitra Lamarck 222
204. maura Swainson 222
Geuus Mitromorpha A. Adams 223
205. filosa Carpenter 223
206. intermedia, sp. nov 223
Family L VII. Fasciolariida: 224
Subfamily Fusime 224
Genus Fusus Lamarck 224
207. barbarensis . Trask 224
208. luteopictus Dall 225
209. robustus Trask 226
210. rugosus Trask 226
Genus Pisauia Bivona 227
211. fortis Carpenter 227
Family L VIII Biiccinidm 227
Genus Chrysodomns Swainson 227
212. rectirostris Carpenter 228
213. tabulatus Baird 228
214. sp. indet 229
Genus Sipboualia A. Adams 229
215. kellettii Forbes 229
Geuus Macron H. & A. Adams 230
216. kellettii A. Adams 230
217. lividus A. Adams 230
Family LIX. Nassidie 230
Genus Nassa Lamarck 230
218. califoruiaua Conrad 231
219. cerriteusis, sp. nov 231
220. fossata Gould 232
221. insculpta Carpenter 233
80 CALIFOENIA ACADEMY OF SCIENCES.
MOLLUSCA (Continued).
■222. meudica Gould 233
223. meudica Gould, var. cooperi Forbes 234
224. perpinguis Hinds 234
225. tegula Reeve 235
226. versicolor C. B. Adams, var. hooveri, var. uov 2,36
Family LX. Cobnnhcllithie 236
Genus Columbella L.4marck 236
227. solidula Reeve, var. pra^cursor, var. uov 236
Subgenus Anachis H. & A. Adams 237
22S. (A.) minima, sp. uov 237
Subgenus jEsopus Gould 237
229. (iE.) chrysalloidea Carpenter 237
230. (.S;.) oldroydi, sp. uov 238
Subgenus Astyris H. & A. Adams 238
231. (A.) califoruiaua Gaskoin. 238
232. (A.) gausapata Gould 239
233. (A.) gausapata Gould, var. carinata Hinds 240
234. (A.) tuberosa Carpenter 240
Genus Amphissa H. & A. Adams 241
235. corrugata Reeve 241
236. ventricosa, sp. uov 242
237. versicolor Dall 242
Fa7nUy LX/. Murkithx ' 243
Genus Murex Linne 243
Subgenus Chicoreus Montfort 243
238. (C.) leeanus Dall 243
239. (C.) trialatus Sowerby 243
Subgenus Pteronotus Swainson 244
240. (P.) festivus Hinds 244
Subgenus Pterorhytis Conrad 244
241. (P.) foliatus Martyn 245
242. (P.) nuttalli Conrad 245
243. (P.) mouoceros Sowerby 246
Genus Mouoceros Lamarck 246
244. engonatum Conrad 246
245. lapilloides Conrad 247
Genus Chorus Gray 247
246. belclieri Hinds 247
Genus Euplenra H. & A. Adams 248
247. muriciformis Broderip 248
248. muriciformis, var. curta, var. uov 249
Genus Trophou Montfort 249
Subgenus Boreotrophou Fischer 249
249. (B.) cerritensis, sp. uov 249
250. (B.) gracilis Perry 250
251. (B.) multicostatus EsniscHOLTZ 251
252. (B.) pedroana, sp. uov 251
253. (B.) scalariformis Gould 252
254. (B.) stuarti Smith 252
255. (B.) orpheus, var. praacursor, var. uov 253
256. (B.) tenuisculptus Carpenter 253
257. (B.) triaugulatus Carpenter 254
Geuus Ocinebra Leach 254
258. barbareusis Gabb 254
259. foveolata Hinds 255
260. interfossa Carpenter 255
261. keepi, sp. uov 256
262. lurida Middendorff 256
263. lurida Midd., var. aspera Baird 257
ARNOLD — THE PALEONTOLOGY AND STKATIGRAPHY OF SAN PEDKO. 81
MOLLUSCA (Continued).
264. lurida Midd., var. cancellina Philippi 257
265. lurida Midd., var. cerritensis, rar. dot 258
266. lurida Midd., var. munda Carpenter 258
267. micheli Ford 259
268. perita Hinds 259
269. poulsoui NnxTALL 260
Subfamily Purpurinm 260
Genus Purpura Beuguiere 260
270. crispata Chemnitz 261
271. saxicola Valenoienne.s 261
Subfamily Coralliophilince 262
Genus Coralliophila H. & A. Adams 262
272. nux Reeve 262
Suborder Streptodonta 262
SUPERFAMILY PTENOOLOSSA 262
, Family LXII. SeaUdce 262
Genus Scala Humphrey 262
273. bellastriata Carpenter 263
274. erebricostata Carpenter 263
275. hemphilli Dall 264
276. hindsii Carpenter 264
277. indianorum Carpenter 264
278. tincta Carpenter 265
Genus Opalia H. & A. Adams 266
[S. D.] anomala Stearns 266
279. borealis Gould 266
280. crenatoides Carpenter, var. insculpta Carpenter. .. . 267
[S. D.] varicostata Stearns .' 267
SUPERFAMILY GYMNOGLOSSA 268
Family LXI 1 1. Eulimidte 268
Genus Eulima Eisso 268
281 . falcata Carpenter 268
282. hastata Sowbrbt 268
283. micans Carpenter 269
Family LXI V. Pyramidellidm 269
Genus Turbonilla Risso 269
Section Strioturbonilla Sacco 270
284. (S.) muricata Carpenter 270
285. (S.) similis C. B. Adams 270
286. (S.) stearnsii Dall & Bartsch, sp. uov 271
287. (S.) torquata Gould 271
288. (S.) torquata var. stylina Carpenter 272
Section Lanoea Pease 272
289. (L.) aurautia Carpenter 272
290. (L.) tridentata Carpenter 273
291. (L.) peutalopha Dall & Bartsch, sp. nov 274
Section Pyigiscus Philippi 274
[S. D.] (P.) auricoma Dall & Bartsch, sp. nov 274
292. (P.) latifuudia Dall & Bart.sch, sp. nov 275
293. (P.) teuuicula Gould 275
294. (P.) crebriHlata Carpenter 276
295. (P. ) subcuspidata Carpenter 277
Section Pyrgisoulus Monterosato 277
296. (P.) laniinata Carpenter 277
Section Pyrgolampros Sacco 278
297. (P.) lowei Dall & Bartsch, sp. nov 278
[S. D.] (P.) lowei var. pedroaua Dall & Bartsch, var. nov. . 279
298. (P.) arnoldi Dall & Bartsch, sp. nov 279
299. (P.) gibbosa Carpenter 279
( 11 ) June 16, 1903.
82 CALIFORNIA ACADEMY OF SCIENCES.
MOLLUSCA (Continued).
300. (P.) adleri Dall & Bartsch, sp. nov 280
Geuus Pyramidella Lamarck 280
301. (P.) oonica var. variegata Carpenter 280
Geuus Odostomia Fleming 281
Section Odostomia (Fleming) s. s 281
302. (0.) tenuis Carpenter 281
Section Evalea A. Adams 281
[S. D.] (E.) stearnsii Dall & Bartsch, sp. nov 282
303. (E.) gouldii Carpenter 282
Section Amaura Moller 282
[S. D.] (A.) pupiformis Carpenter 283
304. (A.) uuciformis Carpenter, var. avellana Carpenter. 283
Section Chrysallida Carpenter 283
[S. D.] (C.) diegensis Dall & Bartsch, sp. nov 284
Section Oscilla A. Adams 284
[S. D.) (O.) aaquisculpta Carpenter 284
[S. D.) (0.) gramniatospira Dall & Bartsch, sp. nov 285
Subgenus Ivara Dall & Bart.sch, subgen. nov 285
305. (I.) terricula (Carpenter) Dall & Bartsch 285
SUPERFAMILY TMNIOGLOSSA 285
Family LX V. Trilonidw 285
Genus Tritonium Link 285
306. gibbosus Broderip 286
Subgenus Priene H. & A. Adams 286
307. (P.) oregonensis Redfield 286
Geuus Ranella Lamarck 287
308. californica Hinds 287
Family LX VI. Cypraida 288
Genus Cypriea LiNNfi 288
309. spadicea Gray 288
Genus Trivia Gray 288
310. californica Gray 288
311. solandri Gray 289
Genus Erato Risso 289
312. columbella Menke 289
Family LX VII. Triforidm 290
Genus Triforis Deshayes 290
313. adversa Montagu 290
SUPERFAMILY CERITHIACEA 290
Family LX VIII. Cerilhiopsidce 290
Genus Seila A. Adams 290
314. assimilata C. B. Adams 290
Family LXIX. Cerithiidm 291
Genus Bittium Leach 291
315. asperum Gabe 291
316. californicum Dall & Bartsch 291
317. filosum Gould 292
318. quadrifilatum Carpenter (with evolutionary discus-
sion of several species) 292
319. rugatum Carpenter 295
320. williamsoni, sp. nov 295
Subgenus Styliferina A. Adams 295
321. (S.) tenuisculpta Carpenter 296
Genus Diastema Deshayes 296
322. sp. indet 296
Genus Cerithidea Swainson 296
323. californica Haldemann 296
Family LXX, Ccecidx 297
Arnold— THK paleontology and stratigraphy of san pedro. 83
MOLLUSCA (Continued).
Genus Csecum Fleming 297
324. californiciim Dall 297
325. crebricinctum Carpenter 298
326. magnum Stearns 298
Family LXXI. Vermelidce 299
Genus Serpulorbis Sassi 299
327. squamigerus Carpenter 299
Subgenus Vermicularia Lamarck 299
328. (V.) sp. indet 299
Genus Spiroglyphus Dacdin 299
329. lituella Morch 299
Family LXXU. Turrilellida: 300
Genua Turritella Lamarck 300
330. cooperi Carpenter 300
331. jewettii Carpenter 300
Family LXXI II. Litlorinidce 301
Genus Littoriua Ferd.ssac 301
332. planaxis (Nuttall) Philippi 301
333. scutulata Gould 302
Genus Lacuna Turton 302
334. compacta Carpenter 302
335. porrecta Carpenter 303
336. solidula (Loven) Carpenter 303
Family LXXI V. Fossaridm 304
Genus Fossarus Philippi 304
Subgenus Isapis H. <fe A. Adams 304
337. (I.) fenestrata Carpenter 304
family LXX V. Bissoidie 304
Genus Kissoa Freminville 304
338. acutelirata Carpenter 305
Subfamily Hydrobiince ,305
Genus Paludestrina d'Orbigny '. 305
339. curta, sp. uov 305
340. stokesi, sp. nov 305
Family LXX VI. Calypirceidce 306
Genus Crucibulum Schumacher 306
Section Crucibulum s. s 306
341. (C.) spinosum Sowerby 306
Genus Galerus Humphrey 307
342. mammillaris Broderip 307
Genus Crepidula Lamarck 307
343. aculeata Gmelin 308
344. adunca Sowerby 308
345. dorsata Broderip 309
346. graudis Middendorff 309
347. navicelloides Nuttall 310
348. onyx Sowerby 310
349. rugosa Nuttall 311
Family LXX VII. Amaltheidce 31 1
Genus Hipponyx De France 311
.350. antiquatus Linn 312
351. cranioides Carpenter 312
352. tumens Carpenter 313
Family LXX VIII. Nalicidce 313
Genus Natica (Adanson) Scopoli 313
Subgenus Cryptonatica Dall 313
353. (C.) clausa Broderip & Sowerby 313
Genus Polyuices Montfort 314
Subgenus Neverita Risso 314
354. (N.) recluziana Petit 314
84 CALIFOKNIA ACADEMY OF SCIENCES.
MOLLUSCA (Continued).
Subgenus Lunatia 315
355. (L.) lewisii Gould 315
Geuus Sigaretus Lamarck 316
356. debilis Gould 316
Family LXXIX. Lamellanidie 317
Geuus Lamellaria Montagu 317
357. steainsii Dall 317
SUPERFAMILY DOCOGLOSSA 317
Family LXXX. Acmceidce 317
Geuus Acmsea EscH. 317
358. depicta Hinds 317
359. insessa Hinds 318
360. instabilis Gould 318
361. mitiaEscH 318
362. paleacea Gould 319
363. pelta Esch 319
364. spectrum (Nuttall) Keeve 320
Family LXXXI, Lioliidce 320
Geuus Delphiuoidea Brown 320
[S. D.] corouadoeusis, sp. nov 320
Family LXXXI I . Phasianellidm 321
Genus Pliasianella Lamarck 321
365. compta Gould 321
Family LXXXI 11. Turhinidm 321
Geuus Paohypoma Gray 321
366. iuaiquale Martyn 321
Genus Pomaulax Gray 322
.367. uudosus Wood 322
Genus Leptotbyra Carpenter 322
368. bacula Carpenter 323
369. carpeuteri Pilsbry 323
370. paucicostata Dall 323
Family LXXXI V. Trochidce 324
Genus Chlorostoma Swainson 324
371 . aureotiuctum Forbes 324
372. biunneuni Philippi 324
373. fuuebrale A. Adams 325
374. fuuebrale A. Adams, Tar. subapertum Carpenter 325
375. gallina Forbes 326
376. montereyi Kiener 326
Subgenus Omphalius Philippi 327
377. (0.) viridulum var. ligulatum Menkb 327
Genua Thalotia Gray 327
378. caffea Gabb 327
Geuus Phorcus Risso 328
379. pulligo Martvn 328
Geuus Calliostoma Swainson 329
380. auuulatum Martyn 329
381. oaualiculatum Martyn 329
382. costatum Martyn 330
383. gemmulatum Carpenter 330
384. tricolor Gabb 331
Genus Norrisia Bayle 331
385. norrisii Sowerby 331
Genus Margarita Leach 3.32
386. optabilis Carpenter, var. kuechti, var. nov 332
387. optabilis Carpenter, var. nodosa, var. uov 332
388. parcipicta Carpenter, var. pedroaua, var. nov 333
389. pupilla Gould 333
Genua Solariella S. Wood 334
AENOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 85
MOLLUSCA (Continued).
390. cidaris A. Adams 334
391. peramabilis Carpenter 335
Family LXXX V . Cydostremalidce 335
Genus Vitrinella C. B. Adams 335
392. williamsoni Dall 335
SUPERFAMILY ZYGOBRAXCHIA 336
Family LXXX VI. ITaliotidce 336
Genus Haiiotis Linne 336
393. fulgens Philippi 336
Family LXXX VII. Fissurellidm 337
Subfamily Fissurellideinae 337
Genus Lucapiua Gr.\y 337
394. crenulata Sowerey 337
Subfamily Emarginulince 337
Genus Fissuridea Swainson 337
395. aspera EscH 338
396. iuEequalis Sowerey 338
397. murina (Carpenter) Dall 339
Genus Clypidella Swaixson 339
398. bimaculata Dall 339
399. callomarginata Carpenter 340
Genus Fissurella Beuguiere 340
400. volcano Reeve 340
Genus Puncturella Lowe 341
401. cucuUata Gould 341
402. galeata GonLD 341
SUBCLASS ISOPLEDRA 342
Order Polyplacophora 342
SUPERFAMILY EOGHITONIA 342
Family LXXX VIII. Chiionida 342
Genus Ischnochiton Gray 342
403. regularis Carpenter 342
Genus Cryptochiton Middendorfe & Gray 342
404. stelleri Middendorff 342
SUPERFAMIL Y OPSICHITONIA 343
Family LXXXIX. MopaliidcE 343
Genus Mopalia Gray 343
405. cillata Sowerey 343
ARTHROPODA .* 344
CLASS VIII. CRUSTACEA 344
SUBCLASS EUCEUSTACEA 344
SuPERORDER ClRRlPEDlA 344
Order Thoracica 344
Family XC. Balanidce 344
Genus Balanus Lister 344
406. concavus Bronn 344
SaPERORDER Malacostraca 345
Order Decapoda 345
Suborder Brachycra 345
Family (Subtribe) XCI. Cancroidea 345
Section Cancrini 345
Genus Cancer Linne 345
407. breweri Gaee 345
VERTEBR ATA 346
CLASS IX. PISCES 346
Order Elasmoeranchii 346
Suborder Selachii 346
Family XCI I. Trygonida: 346
Genus Urolophus 346
408. halleri (?) Cooper 346
86 CALlFOKSfIA ACADEMY OF SCIENCES.
CCELENTERATA/
Class ANTHOZOA.-
Family I. TURBlNOLIDiE.
Genus Caryophyllia Lamarck.
I. Caryophyllia arnoldi Vaughan.
Plate III, Figs. 4 and 4a.
Caryophyllia arnoldi Vaughan, Proc. U. S. Nat. Mus., Vol. XXII, 1900, No. 1194, pp. 199, 200,
PL XVI, figs. I, 2.
The following is the original description: —
Form of corallum slightly deformed inverted cone-shaped. A basal scar present, but the coral
in its later stages was evidently unattached. Base subacute, calice nearly circular in transverse outline.
Costae very distinct, low, broad, rounded, or flattish, show no ornamentation, but the speci-
men is worn, and they were probably minutely granulated, There is a tendency to alternation in
size, which is pronounced near the base. There is no observable epitheca. The wall is stout, solid,
a distinct pseudotheca. The costae are wide and the intercostal spaces very narrow, simply furrows,
and the septa are thickened at the wall. The upper margins of the septa project very slightly above
the upper limit of the corallum wall. There are four complete cycles of septa (forty-eight in all),
arranged as follows: Twelve large thick septa, joined to the columella by very thick pali. The
width of each palus is equal to the width of its corresponding septum; the upper margins of the
palus stand about 2 mm. above the upper surface of the columella, and fully i mm. above the notch
dividing the palus from the septal lamina. The width of the pali is about 2.5 mm. From the upper
margin of the septum to the notch between septum and palus is about 4.5 mm., maybe slightly
greater. The inner ends of the pali are fused solidly around the columella and to it. On the septal
faces are small granulations arranged in curves parallel to the upper septal margins. On the faces
of the pali are granulated or serrated crests arranged in curves parallel to the upper margins of the
pali. Between each pair of these larger septa are three smaller (one of the third cycle and two of
the fourth). The members of the third cycle are narrow above the level of the upper termination
of the columella; below this they widen, but do not seem ever to reach the columella. The members
of the fourth cycle are narrow, and thin e.xcept where they arch over the walls. The columella is
essential, is composed of several pieces, trabeculse, which are firmly soldered one to another and to
the inner terminations of the pali by solid basal calcareous deposit. From the upper margins of the
septa to the upper termination of the columella is about 6.5 mm. ; that is, the caiicular fossa is about
6.5 mm. deep. The greater diameter of the upper termination is 5 mm., the lesser 3.5 mm., above
whose level, as may be gathered from what preceded, the pali form a regular crown.
Dime?isions. — Greater diameter of calice, 16 mm.; lesser diameter of calice, 15.3 mm.;
height of corallum, 16.5 mm.; depth of fossa, about 6.5 mm.
Locality. — San Pedro Hill, San Pedro, California.
Geologic Horizon. — Pleistocene.
Type.— C-At. No. 157,509, U. S. National Museum.
1 The general arrangement of the claaaea is that used by Eastman in Zittel's Text-Book of Paleontology.
2 Mr. Wayland Viiughan. of the United States Geological Survey, has prepared the dlagnoseB of the new Authozoa which have
been found in the San Pedro deposits. These descriptions are here included in this paper.
ARNOLD— THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 87
2. Caryophyllia pedroensis Vaughan, sp. nov.
Plate III, Figs. 3 and 3a.
Corallum cornute, transverse calicular outline broadly elliptical.
The outer surface of the specimen is worn, so that the detail of the ornamentation is
destroyed, but it can be discovered that the costae were not very prominent, and that there were
twelve corresponding to twelve large septa, pronouncedly larger than the others.
The septa are in four complete cycles; the members of the first and second cycles reach
the columella and are rather thick, especially around the columella ; those of the third are shorter
and thinner, and those of the fourth still smaller. The septa are not so thick as in C. arnoldi, and
not so crowded as in C. californica. The septal faces are granulated, the granulations being much
larger and with blunt ends near the columella. All the pali except one are broken off, but they
appeared to e.xist before the twelve larger septa. The one remaining palus is broad and thin.
Calice fairly deep. Upper surface of the columella not very deeply sunken below the level
of the upper edge of the pali. Columella composed of several twisted pieces.
Dimejisions. — Greater diameter of calice, 13.5 mm.; lesser diameter ol calice, 12 mm.;
height of corallum, 25.5 mm.
Locality. — San Pedro, California.
Oeologic Horizon. — Pleistocene.
^yj'je. — From the collection of Raljjh Arnold.
3. Caryophyllia californica Vaughan, sp. nov.
Plate III, Figs. 2 and 2a.
Corallum with a narrow base, the lower half slender in comparison with the diameters at the
calice. The tip of the base damaged. Calice elliptical in transverse outline.
The outer surface of the corallum is scarcely costate. There are flat, indistinct, densely
granulate costte corresponding to the septa, visible especially at and just below the calicular edge.
The wall is thin and fragile.
There are four complete cycles of septa and many members of the fifth. They are thin and
crowded, twelve are larger than the others, and apparently these twelve bore pali on their inner
terminations. The margins of the septa of the first and second cycles project slightly above the
upper edge of the wall, about i mm.; the margins of the septa of the other cycles are not prominent.
The septal faces are granulated, the granulations are low, frequently showing elongation along the
courses of the septal trabeculae ; the usual arrangement in curves parallel to the septal margins also
is shown. Calice fairly deep, 4.5 or 5 mm.; a distinct and rather sudden depression over the
columella. Columella not greatly developed, composed of a few loosely twisted laths.
Dimeiisions. — Greater diameter of calice, 1 1.5 mm. ; lesser diameter of calice, 10 mm. ; height
of corallum, 13 mm.
Locality. — Deadman Island, off San Pedro, California.
Geologic Horizon. — Pliocene.
Type. — From material sent by Mr. Ralph Arnold to the U. S. National
Museum.
88 califoknia academy of sciences.
Differential Characters of the Three Californian Species of Caryophyllia.
Septa in four cycles ( form coruute; twelve more prommeut costas ) C. pedroensis
I form short, inversely subcouical, cost;© i
^ eqnal near the calice, alternating iu size [ C. arnoldi
( near base )
Septa in four com- 1 j
plete ej'cles, many ) form subflabellate, costne excepting near the I p ,. ,
members of the tifth 1 calicular margin indistinct ( ' ^" ijormca
present ( )
As the descriptions and the above table show, for the differentiation of the spe-
cies, especial stress is laid upon the number of the septa, the form, and the costal charac-
ters. Although each of the three species is based on a single specimen, the author does
not believe it possible for intergradation to occur within the horizons from which
they were collected. C. pedroensia and C. arnoldi appear to belong in the same
group (section) of the genus; but C. califomica presents great and striking differ-
ences from each of the preceding.
Genus Paracyathus Milne-Edwards & Haime.
Verrill has described three species of Paracyathus from the west coast of
North America, viz.: Paracyathus caltha,^ Paracyathus stearnsij^ and Paracyathus
humilis.^ The first two species mentioned are from Monterey, California; the last
mentioned is from the Pearl Islands.
Expressed in tabular form the differences between these three species are: —
f CostiTB distinct only at edge of calice, be- 1
„ ,, K • < I low represented by rows of granules; axes of > P. callha
Uorallum 5 in or ^^,j^^ ^^ in. /.32 in
more in height; nve J ' '
complete cycles of j glabrous, subequal costaa, distinct to base, ^
^ P^ I near base every fourth or sixth costa more ; P. slearnsi
{ prominent; axes of calice, .72 in. /.50 iu . . . . )
i^ora nm ori y ._ n. i Q^g^.g feeble, except near calicular margin. / „ i -i-
in height; four com- diameter of circular calice, .22 in ^- ^«»"'"
plete cycles of septa. ( )
According to the diagnostic characters given by Verrill, these three species
are very distinct.
4. Paracyathus pedroensis Vaughan, sp. nov.
Plate III, Figs. 1 and la.
Corallum subturbinate in shape, base damaged, apparently not especially expanded; trans-
verse outline of calice elliptical, slightly deformed.
Costse not prominent, but distinct from the calicular margin to the base, subequal, some-
times every third or every fifth may be slightly more prominent than those intervening, the edges
usually flattish, sometimes slightly crested. Bottoms of the intercostal furrows usually flattish;
granulations crowded on the costse, and present in the intercostal furrows also.
1 Proc. Boat. Soc. Nat. Hist., Vol. XII, 1869, p. 394; Trans. Conn. Acad. 8ci., Vol. I, 1870, p. 637, Pi. IX, figs. 9, 9a.
" Proc. Bost. Soc. Nat. Hist.. Vol. XII, 1869, p. 393; Trans. Conn. Acad. Sci., Vol. I, 1870, p. 537.
'Trans. Conn. Acad. Sci., Vol. I. 1870, p. 638.
* These decimals of an inch can be computed into millimeiers by reckoning ,1 inch = 2.6_mm.
ARNOLD— THE PALEONTOLOGY AND STKATIGEAPHY OF SAN PEDKO. 89
There are four complete cycles of septa, and many members of the fifth, but the fifth is not
complete. The septal margins project very slightly above the upper margin of the corallum wall;
the margins of the members of the first and second cycles, and those of the third cycle when members
of the fifth are present, are slightly more prominent than the margins of the members of the higher
cycles. The septal faces are densely granulated, and the granulations show a decided tendency
toward elongation along the courses of the septal trabecule. The septa are crowded, those of the
first, second, and third cycles are thick and strong; when members of the fifth cycle are present those
of the fourth are quite thick, but are thinner than the older septa.
The pali are well developed, and are shown in great perfection on the type specimen.
They are broad and simple, and not bilobed. Those before the septa of the first cycle are the nar-
rowest; those before the septa of the second cycle are slightly wider, and those before the septa of
the third cycle are still wider. The inner margins of the pali before the septa of the first, second, and
third cycles form a crown bordering the outer edge of the columella. In those half or quarter sys-
tems in which septa of the fifth cycle are present, pali stand before the members of the fourth cycle.
These pali are large, but stand back from the columella. In such cases the pali join the members of
the fourth cycle to the sides of the included members of the third. When no pali are present the
members of the fourth fuse by their inner margins directly to the side of the included member
of the third. When members of the fifth cycle are present, they curve toward the included
member of the fourth. There are no pali before the youngest septa in any given system. Margins
of the pali entire.
The calice is shallow, widely open Its ends, corresponding to the ends of the longer trans-
verse axis, are very slightly depressed. The upper surface of the columella is flat; it consists of the
rounded upper terminations of a large number of papillee. The pali, excepting those of the fourth
cycle, form a crown around the columella, as has already been stated.
Dimensions. — Greater diameter of calice, 12 mm.; lesser diameter of calice, 10 mm.; height
of corallum, i8-|- mm.
Locality. — San Pedro, California.
Geologic Horizon. — Pleistocene.
Type. — From the collection of Ralph Arnold.
If the description first given is compared with the table showing the chief
diagnostic features of Verrill's species, it will be evident that the only species with
which comparison needs to be made is P. stearnsi. At the same time, certain strik-
ing differences between the two will be very evident. The first is one of size.
p. stearnsi. . .
P. pedroensis
Greater Diameter of
Calice.
18mm.
12 mm.
Lesser Diameter of
Calice.
12.5 mm.
10 mm.
Height of
Corallum.
12.5 mm.
18-f- mm.
The costje and the number of septa are different in the two species, but a
much more important difference has not yet been brought out in the discussion.
Verrill says of the septa and pali in P. stearnsi: "The primary and secondary
septa are considerably broader than the others, broadly rounded and somewhat exsert
at summit, narrowed toward the base, and divided into tivo or three unequal, broad,
stout, paliforvi teeth, which are rough and lacerately spinulose at summit " '
1 The italics are used by the author of the prefient paper.
, 12 ) October 28, 1902.
90 CALIFOENIA ACADEMY OF SCIENCES.
As stated in the present description, the pali of P. pedroensis are not lohecl and
their margins are entire.
These comparisons will show how strikingly different the present species is
from any of those previously described species from the west coast of North America.
ECHINODERMATA.
Class ECHINOIDEA/
Subclass EUECHINOIDEA.
Order DIADEM ATOI DA.
Suborder STEREOSOMATA.
Family II. ECHINOMETRID^E.
Genus Strongylocentrotus Brandt.
Test symmetrical and polyporus. Amb straight, broad at the ambitus and peristome, and with
broad, poriferous zones. Pairs of pores in oblique arcs, or almost transverse series of from four to
ten pairs, and crowded actinally. Interporiferous areas with two vertical rows of plain, imperforate
primary tubercles ; secondaries and miliaries also present. Amb with two rows of primary, and four
or more of secondary tubercles.
5. Strongylocentrotus franciscanus A. Agassiz.
Toxocidaris franciscana A. Agassiz, Bull. Mus. Comp. Zool., Vol. i, 1863 ijide Clark.)
This is the large sea-urchin of the West Coast. Spines which are probably of
this species have been found in tlie lower San Pedro series of Deadman Island. The
spines of this species are distinguishable by their large size and longitudinal striations.
Some of the spines found are 20 mm. long and o mm. in diameter.
Living. — Puget Sound; San Diego (H. L. Clark).
Pleistocene. — San Pedro (Arnold).
6. Strongylocentrotus purpuratus Siimpson.
Echinus purpuraius Stimpson, Crustacea and Echinoderms of the Pacific Coast, 1857 {,fide Clark.)
Numerous spines of this small purple sea-urchin have been found in the San
Pedro series. No part of the test has ever been discovered in these deposits, to the
writer's knowledge. Several nearly perfect tests of this species were found in the
* The classlficatiou auU geueric descriptious for tblsclaes are ftoui Eaetmau iu Zittel's Text Book of Paleoutology.
ARNOLD — THE PALEONTOLOGY AND STRATIGKAPHY OF SAN PEDRO. 91
Pleistocene (lower San Pedro series) deposits at the bath-house, Santa Barbara.
A nearly perfect test was also found in the upper horizon of the San Diego
formation ( Pleistocene (?) at Pacific Beach, near San Diego.
Living. — San Francisco; Puget Sound (H.L.Clark): San Pedro (Arnold).
Pleistocene. — San Pedro; Santa Barbara; San Diego (Arnold).
Order CLYPEASTROIDA.
Family III. SCUTELLIDiE.
Genus Scutella Lamarck.
Test circular or subcircular in outline, sometimes undulating or notched, broadest behind ;
petaloid parts of the amb unequal, well developed, nearly closed. Peristome small, central, subcir-
cular. Periproct very small, inframarginal. Apical system central, more or less pentagonal.
Subgenus Echinarachnius Leske.
Apical system eccentric in front or behind. Periproct actinal, marginal or supramarginal.
7. Scutella (Echinarachnius) excentricus Eschscholtz.
Scutella excenUica EscH., Zool. Atlas, PI. XX, fig. 2, 1826.
Echinarachnius excentricus EscH., Valenciennes, Voyage Venus, PI. X, i9i^6;^=Scutella siriaiula
Con. {Jide Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 271). Merriam, Bull. Dept.
Geol., Univ. of Cal., Vol. II, 1898, p. no; Proc. Cal. Acad. Sci., 3rd Ser., GeoL, Vol. I^
1899, p. 170, PI. XXII, fig. 8.
Test quadrate-oval in outline ; upper surface arched, summit behind the middle of the long
diameter, but in front of the excentric apical system ; petals broad, open at ends ; posterior laterals
wide apart, ovate in outline, one-half the length of the anterior pair ; anterior petal longer than the
anterior laterals, scattered pores continue some distance beyond the end ; apical shield excentric, its
distance from the posterior margin being to its distance from the anterior margin as i to 1.8+ : the
ambulacral furrows are split up into a great number of small branches, of which the strongest pass
over the margins and extend over the upper surface ; four of the strongest furrows run to the lateral
petals and stretch through their median areas almost to the apical system ; those furrows not passing
to the petals sometimes reach half way to the apical system.
Dimensions. — Long. 63 mm.; lat. 68 mm.; alt. 8 mm.
Specimens from the lower San Pedro series of Deadraan Island, and upper
San Pedro series of San Pedro and Los Cerritos w^ere submitted to Dr. Merriaiu, who
pronounced them typical E. excentricus. This is the common "Sand Dollar" of the
Pacific Coast.
Living. — Alaska to San Pedro (Cooper).
Pleistocene. — San Pedro (Cooper; Arnold) : San Diego; Santa Barbara (Arnold)
(?) Pliocene. — Seven Mile Beach, San Mateo County; San Fernando; (?) San
Diego (Cooper): (?) San Gregorio Creek, San Mateo County (Barber).
92 CALIFORNIA ACADEMY OF SCIENCES.
MOLLUSCOIDEA.
Class BRYOZOA.
8. Bryozoa sp. indet.
Small pieces of branching bryozoa are found quite abundantly in the San
Pedro series; but as no diagnoses of West Coast species are available, their generic
and specific relations cannot be given. Among some material sent to Dr. Dall, and
identified by him, were several specimens which he labeled '■'CiqyuUfera sp." These
little saucer-shaped bryozoa are from the upper San Pedro deposits, at the lumber-
yard, north end of the San Pedro bluff.
Class BRACHIOPODA.'
Order ARTHROPOMATA.
Family IV. TEREBRATULIDvE.
Genus Terebratalia Bcecher.
Shell smooth or radially plaited; dorsal valve longitudinally impressed; hinge-line straight
or not much curved; beak with a flattened area on each side of the deltidium; foramen large; del-
tidium incomplete; loop attached to the septum.
IWebratalia obsoleta Dall is a characteristic species.
[S. B.y Terebratalia hemphilli Dull.
Plate XVII, Figs. 1, 2 and 3.
Terebratalia hemphilli Dall (mss.)
Shell of medium size, subcircular in outline, rather thin ; brachial valve with mesial flexure
concave ; surface of this valve sculptured by numerous fine incremental lines, and very faintly near
the apex by several radiating lines ; pedicle valve mesially convex, the sculpture being as in the
brachial valve.
Dimensions. ^V^on^. 56 mm.; lat. 57 mm.; diam. 30 mm.
This species may be distinguished from T. mntlii by its broader outline, larger
foramen, and nearly smooth surface. T. hemphilli is a form which shows much
variation both as regards its outline, degree of convexity or concavity of its valves,
and its sculpture. The drawings of this species were made by Mr. J. Howard
Wilson, who first discovered the species. Found in the Pliocene of Packard's Hill,
Santa Barbara.
FlioceMe. — Santa Barbara (Wilson; Arnold).
^ The claeaificatlon and generic description of this class are from Tryon's *' Structural and Systematic Conchology."
- All species described in this paper, but not occurring in the 8an Pedro fauna, are designated by the initials of the locality from
whence they are described.
ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 93
9. Terebratalia smithi, sp. nov.
Plate XVII, Fio. 9.
Shell of medium size, subcircular in outline, rather thin ; brachial valve with mesial flexure
concave, surface of this valve sculptured by about thirty small, rounded, radiating ridges and several
prominent incremental lines ; intermediate incremental lines small and inconspicuous ; pedicle valve
quite strongly mesially convex, the surface being sculptured as in the dorsal valve ; beak with a
flattened area on each side of the deltidium ; foramen small. At a length of 20 mm. and before, the
shell is slightly broader proportionately than in the adult.
Dimensions. — Long. 50 mm.; lat. 47 mm.; diam. 23 mm.
T. smithi resembles T. hemphiUi Dall (mss.), but differs from that species by
being much narrower in all stages of growth, liaving a much smaller foramen, and
in being much more prominently sculptured. A large series of T. hemphiUi collected
from the Pliocene at Santa Barbara by Mr. J. Howard Wilson was compared with
the type of T. smithi, and the specimens in every case showed the differences men-
tioned above. The drawings of T. hemphilli (PI. XVII, figs. 1, 2, 3) were made by
Mr. J. Howard Wilson from a specimen obtained at Santa Barbara, and are inserted
here for comparison with the figure of the type specimen of T. smithi. T. hemphilli
has been found so far only in the Pliocene of Santa Barbara.
This species and Laqueus jeffreysi are the only brachiopods which have so far
been found in the San Pedro beds. The type specimen, the only one found, was
obtained by Mrs. Oldroyd from the Pliocene of Deadman Island; it is figured in this
paper, and is now in the collection of Mrs. Oldroyd.
Pliocene. — San Pedro (Oldroyd).
Genus Laqueus Dall.
Shell with the reflected portion of the loop attached by slender processes, on each side, to
the haemal processes, at or near the points where the two septal processes branch off to the septum;
foramen complete.
Type, Laqueus californicus Koch.
10. Laqueus jeffreysi Dall.
Frenula jeffreysi Dall, Am. Nat., Vol. V., 1871, p. 55 (ismeniform stage).
Ismejiia jejfreysi Dall, Am. Jour. Conch., Vol. VII, 1871, p. 65, PI. XI, figs. 7-10.
Megerlia j^t/ffreysi Dall, Sci. Res. Expl. Alaska, 1877, p. 48.
Laqueus californicus var. va7ico2tverensis Davidson, Mon. Rec. Brachiopoda, Trans. Linn. Soc. ,
2nd Sen, Vol. IV., 1887, p. 113, PI. XVIII, figs. 10-13^ (adult), {fide Dall).
Laqueus Jeffrey siViPOA., Proc. U. S. Nat. Mus., Vol. XVII, 1894, p. 725.
Shell subcircular, inflated, with the margins of the valves nearly straight ; surface smooth,
waxen, with close, conspicuous punctations ; area marked by an incised line ; deltidia wanting ; the
two separated parts of the area narrow and very small ; beak of the hremal valve rather prominent,
smooth. Neural beak incurved, truncated, not prominent.
Dimensions. — Long. 35mm.; lat. 35 mm.; diam. 17 mm.
94 CALIFORNIA ACADEMY OF SCIENCES.
Distinguishable externally from L. calif ornicus by thicker shell, waxen rather
than ruddy coloration, and larger foramen. Specimen identified by Dr. Dall.
Specimens which may be of this species ai"e labeled "Z. calif oi'nicus" in the State
Museum collection of fossils at Berkeley. Found in Pliocene of Deadman Island;
two specimens, one by Mrs. Oldroyd. Found in Pliocene of Pacific Beach, near San
Diego, and also in the Pliocene of Packard's Hill, Santa Barbara.
Living. — Aleutian Islands to point off Estero Bay, near San Luis Obispo, (75
to 238 fathoms) Dall.
Pliocene. — San Pedro (Arnold; Oldroyd): Santa Barbara; San Diego (Arnold).
Family V. LINGULID^.
Subfa m ily L I KG UL IN^.
Genus Glottidia Dall.
Shell linguiform, elongate, pedunculated ; dorsal valve provided internally with two sharp,
narrow, incurved laminae, diverging from the beak, and extending about one-third the length of the
shell ; ventral valve with a mesial septum of about the same length, extending forward from the
beak ; anterior adductor impressions rounded ; scar of post-adductor close in cavity of beak,
rounded ; shell smooth, perforate or imperforate.
Type, Glottidia alhida Hinds.
[S. B.] Glottidia albida Hinds.
Lingula albida Hinds, Zool. Sulph., p. 298, PI. XXIX, fig. 4, 1845. G. W. Sowerby, Thes.
Conch., p. 393, PI. LVII, fig. 6, 1846. Davidson, Ann. & Mag. Nat. Hist., 2nd Sen, Vol.
IX, 1852, p. 377. Reeve, Conch. Icon., Monog. Lingula, PI. I, fig. 4, 1859. E. Suess,
Sitz. k. Akad. Wiss. Wien, Bd. XXXVII, 1859, p. 230. Carpenter, Brit. Assn. Rept.
1863, p. 636. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 246. Keep, West Coast
Shells, p. 215, fig. 182, 1892.
Glottidia albida Hinds, Dall, Am. Journ. Conch., Vol. VI, 1870, p. 157, PI. VIII, figs. 1-6; Proc.
Phil. Acad. Nat. Sci. , 1873, p. 204; Scientific Results Expl. Alaska, 1877. Davidson,
Challenger Rept. (Zool.) Vol. I, 1880, p. 26; Recent Brachiopoda, Part 3, 1886, p. 221, PI.
XXVIII, figs. 2-4. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1893, p. 182.
Shell narrow; elongated, oval, linguiform, tapering at the beaks, sides almost subparalleh
very slightly curved in front; rather flat, marked with concentric lines of growth; in interior of ven-
tral valve the beak is pointed, with a small triangular-shaped thickening grooved along the middle;
mesial septum extends for one-third length of valve; scars as in generic description.
Dimensions. — Long. 27 mm.; lat. ir mm.; diam. 5.5 mm.
One perfect valve and two imperfect valves of this species were found in the
Pliocene of Packard's Hill, Santa Barbara.
Living. — Monterey to Magdalena Bay, Lower California (Davidson).
Pliocene. — Santa Barbara (Arnold): San Diego well (Hemphill).
AKNOLD — THE PALEONTOLOGY AND STRATIGBAPHY OF SAN PEDRO. 95
MOLLUSCA.
Class PELECYPODA.'
Order PRIONODESMACEA.
Superfamily NUCULACEA.
Family VI. NUCULID.E.
Genus Nucula Lamarck.
Shell trigonal, with the umbones turned towards the short posterior side; smooth or sculp-
tured; epidermis olive; interior pearly; margins crenulated; hinge with prominent internal cartilage-
pit, and a series of sharp teeth on each side; pallial line simple.
Type, Area nucleus Lam.
Subgenus Acila H. & A. Adams.
Shell with divaricate sculpture.
Niicula divaricaia Hinds is a characteristic species.
II. Nucula (Acila) castrensis Hinds.
Niicula castrensis Hinds, Proc. Zool. Soc. , 1843, p. 98; Zool. Sulph., p. 61, PI. XVII, fig. 5, 1844.
H. &. A. Adams, Gen. Rec. Moll., Vol. II, p. 545. Williamson, Proc. U. S. Nat. Mus.,
Vol. XV, 1892, p. 192.
Acila castrensis Hinds {^=A. lyalli BAiRD,yide Carpenter, Brit. Assn. Rept., 1863, p. 644); {^Nucula
divaricata CoN.^JV. decisa CoN.=N. co/iradi Meek, /ide Gabb, Pal. Cal., Vol. II, 1869, P"
102). Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 227. Williamson, Proc. U.S. Nat.
Mus., Vol. XV, 1892, p. 192. Dall, Trans. Wagner Inst. Sci., Vol. Ill, 1898, p. 572.
Shell small, trigonal, convex, of medium thickness; umbones posterior to center, turned
posteriorly; anterior end longer than posterior, rounded; posterior end short, truncated; surface
divaricately sculptured; hinge with prominent internal cartilage- pit and numerous sharp teeth on
each side.
Dimensions. — Long. 11. 5 mm.; alt. 10 mm.; diam. 8 mm.
Easily distinguishable by the liinge teeth and divaricate sculpture. Speci-
mens identified by Dr. Dall.
Common in Pliocene, rare in lower San Pedro series, of Deadman Island and
San Pedro.
Livincj. — Sitka to San Diego (Cooper).
Pleistocene. — Santa Barbara to San Diego (Cooper): San Pedro (Arnold).
Pliocene. — San Pedro (Arnold) : San Fernando; San Diego well (Cooper).
(?) Miocene. — Oregon; Martinez; Griswold's, San Benito County (Cooper):
Blakely, near Seattle, Washington (Arnold).
1 The major classiticatiou of this class is according to that presented by Dr. W. H. Dall iu Part III of the " Contributions to the
Tertiary Fauna of Florida." The minor details of classificatiou and most of the generic descriptions are from Parts IV and V of the same
work. The rest of the generic descriptions are from Tryon's " Structural and Systematic Conchoiogy."
96 CALIFOKNIA ACADEMY OF SCIENCES.
Subgenus Nucula s. s.
Shell not divaricately sculptured.
Kiicnla obliqua Lam. is a characteristic species.
12. Nucula (Nucula) suprastriata Carpenter.
Plate XVIII, Fig. 6.
(?) Nucula tenuis (iion MoNT.) Carpenter, Brit. Assn. Rept. 1863, p. 644. Cooper, State Mus.
Collection Catalogue.
Shell small, trigonal, convex, thin, white, pearly interior; utnbones turned toward the short
posterior end; posterior end sharply rounded, anterior evenly rounded; surface with numerous dis-
tinct, rounded, raised, concentric lines; interior of margin finely crenulated; hinge with small, interior
cartilage-pit, and numerous sharp teeth on each side.
Dimensions. — Long. 5.8 mm.; alt. 5.2 mm.; diam. 3 mm.
This beautiful little shell is easily distingui.shable by its triangular shape,
numerous sharp teeth, and distinct concentric sculpture. Specimens identified by
Dr. Dall.
Rare in the lower San Pedro series of Deadman Island and San Pedro; and
in the upper San Pedro series of San Pedro; common in the upper San Pedro series
of Los Cerritos. Found also at Spanish Bight, San Diego. The specimen figured
is from the upper San Pedro series at Los Cerritos, and is now in the collection of
Delos Arnold.
(?) Living. — Straits of Fuca to Santa Barbara; Japan (Cooper).
Pleistocene. — San Pedro (Arnold): San Diego (Arnold).
Family VL LEDID.E.
Genus Leda Schumacher.
Shell resembling Nucula; oblong, rounded in front, produced and pointed behind; margins
even; pallial line with a small sinus; umbonal area with a linear impression joining the anterior
adductor.
Leda pernula Mull, is a characteristic species.
13. Leda fossa Baird.
Plate XVII, Fig. 7.
Leda fossa Baird, Proc. Zool. Soc, 1863, p. 71. Carpenter, Brit. Assn. Rept., 1863, p. 644.
Dall, Nat. Hist. Soc. British Columbia, Bull, No. 2. 1897, p. 7, PI. II, figs. 3, 13.
Shell small, elongate, convex, thin; umbones anterior, turning slightly toward the posterior
end, which is elongated, narrow and truncated; anterior end short and evenly rounded; sculpture
nearly obsolete, a few concentric lines discernible; escutcheon long, narrow, smooth and deep-set; an
elongate process on middle of interior of posterior end; hinge with small internal cartilage-pit, and
numerous sharp teeth on each side.
Dimensions. — Long. 11 mm ; alt. 6 mm ; diam. 3.8 mm.; umbo to posterior end 7.5 mm.;
to anterior end 5 mm.
ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 97
Distinguishable by lack of sculpture. Specimen identified by Dr. Dall.
One specimen from lower San Pedro series of Deadman Island, which is the
one figured, and which is now in the collection of Delos Arnold.
Living. — Puget Sound (Carpenter).
Pleistocene. — San Pedro (Arnold).
14. Leda hamata Carpenter.
Plate XVII, Fig. 4.
Leda hamala Cpr. , Brit. Assn. Rept., 1863, p. 644.
Shell small, elongate-trigonal, convex, thin; umbones anterior, turning slightly toward the
posterior end; short, rounded anteriorly; much lengthened, narrowed and abruptly truncated pos-
teriorly; surface sculptured by strong, concentric raised lines; a raised band, strongly transversely
sculptured by continuations of the concentric ridges, passes from the umbo, around the escutcheon,
to the posterior end; on the interior of the posterior end is an elongated, raised process; escutcheon
deep-set, smooth.
Dimensions. — Long. S mm.; alt. 5 mm.; diam. 2.5 mm.; umbo to posterior end 5.5 mm.;
to anterior end 4 mm.
A small species, readily distinguishable by its long, curved posterior portion,
strong sculpture, smooth escutcheon, and interior posterior process. Specimen iden-
tified by Dr. Dall.
A nearly perfect, united pair from the lower San Pedro series of Deadman
Island; rare; also reported from the Pliocene of Deadman Island. Pleistocene of
Spanish Bight, San Diego. The specimen figured is from the lower San Pedro
series, and is now in the collection of Delos Arnold.
Living. — Santa Barbara to Catalina (Carpenter).
Pleistocene. — San Pedro (Arnold): San Diego (Arnold).
Pliocene. — Deadman Island, San Pedro (Arnold).
15. Leda minuta Fahr. var. praecursor, var. nov.
Pl.\te XVII, Fig. 6.
Shell small, trigonal, conve.x, thin; umbones anterior to middle and turning slightly toward
the posterior side; anterior portion from umbones short and rounded; posterior portion longer,
slightly depressed, produced and slightly truncated; surface sculptured by prominent, raised con-
centric lines; escutcheon long, narrow, slightly striated with continuation of concentric ridges; a flat
sculptured band runs around escutcheon from umbo to posterior end, and on the interior of the shell
at the posterior end of this band is a little elongate ridge or process; hinge with prominent internal
cartilage cup and about fifteen prominent sharp teeth on each side; pallial sinus small, narrow.
Dimensions. — Long. 7.8 mm.; alt. 5 mm.; diam. 3.9mm.; umbo to posterior end 5 mm.; to
anterior end 4 mm.
( 13 ) November 1, 19C'2.
98 CALIFORNIA ACADEMY OF SCIENCES.
Distinguishable from L. ttvphria by smaller size, truncated posterior end with
process on interior at this end, comparatively coarser sculpture, straighter posterior
dorsal margin, and fewer teeth. The type shows two concentric furrows, one at 2.5
mm. and the other at 4 mm. from the umbo, which are probably the result of inter-
rupted growth. Specimens identified by Dr. Dall, who pronounced them a variety of
Z. minuta Fabr., a northern species.
Rare in lower San Pedro series of Deadman Island and San Pedro. The
specimen figured is the type, which is from the lower San Pedro series at Deadman
Island, and is now in the United States National Museum.
Pleistocene. — San Pedro (Arnold).
i6. Leda taphria Dull.
Plate XVII, Fig. 5.
Leda taphria Dall, Nat. Hist. Soc. British Columbia, Bull. No. 2, 1897, p. 7, PI. II, figs. 6 and 8
{^ccrlata Hds., 1844, not Conr., \%-i,2\ fide Dall, Trans. Wagner Inst. Sci., Vol. Ill, 1898,
P- 579)-
Nucjila ctzlaia Hds., Proc. Zool. Soc, 1844, P- 99! Zool. Sulph., p. 64, PI. XVIII, fig. 13, 1844.
Leda ccelata Hds., Thes. Conch., Vol. Ill, No. 42, figs. 95, 96. Carpenter, Brit. Assn. Rept., 1863,
p. 644. Gabb, Pal. Cal., Vol. II, 1869, p. 103. Cooper, 7th Ann. Rept. Cal. St. Min., 1888,
p. 245. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 192.
Shell small, trigonal, oblong and rounded in front, produced and pointed behind; surface
sculptured by numerous sharp, concentric, raised lines; umbones central, turned toward posterior
end; escutcheon long, narrow and concentrically striated ; hinge with prominent internal cartilage-pit,
and about twenty sharp teeth on each side; pallial line with a small sinus; umbonal area with a linear
impression joining the anterior adductor.
Dimensions.— \^ong. 19 mm.; alt. 11 mm.; diam. 8 mm.
This is the largest of this genus found in these deposits, and is easily recog-
nized by its size, sculpture and peculiar teeth. Hinds' name, L. cuJata, was preoccu-
pied by a species of Conrad's, and Dall has renamed Hinds' species for that reason.
Specimens identified by Dr. Dall.
Found in Pliocene of Deadman Island and Timm's Point; lower San
Pedro series of Deadman Island and San Pedro; and in the upper San Pedro series
of Deadman Island, San Pedro, Crawfi,sh George's, Los Cerritos, and Long Beach.
Found also in the Pliocene of Pacific Beach, and in the Pleistocene of Spanish Bight
and Pacific Beach, San Diego. The specimen figured is from the lower San Pedro
series at Deadman Island, and is now in the collection of Delos Arnold.
Living. — Bodega Bay to San Diego (Cooper).
Pleistocene. — Santa Barbara to San Diego (Cooper) : San Pedro; San Diego
(Arnold).
Pliocene. — San Fernando; San Diego well (Cooper): San Pedro; San Diego
(Arnold).
ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 99
Miocene. — Walnut Creek, Contra Costa County; Griswold's, San Benito
County; San Juan Capistrano, San Diego County (Cooper).
Genus Yoldia Moller.
Shell oblong, slightly attenuated behind; compressed, gaping, smooth or obliquely sculp-
tured, with a dark olive, shining epidermis; external ligament slight; cartilage as in Leda; pallial
sinus deep.
Yoldia myalls. Coutli. is a characteristic species.
17. Yoldia cooperi Gahh.
Yoldia cooperi Gabb, Proc. Cal. Acad. Sci., Vol. Ill, 1865, p. 189; Pal. Cal., Vol. II, 1869, p. 31, PI.
IX, fig. 54. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 192. Dall, Trans.
Wagner Inst. Sci., Vol. Ill, 1898, p. 594.
Yoldia inipressa (not of Con., Wilkes Exped., Vol. X, p. 726, PI. XVIII, fig. 13; nor of Meek,
Smithsonian Check - List, Mioc); in part, Gabb, Pal. Cal., Vol. II, 1869, p. 59; in part,
Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 270.
Shell of medium size, oblong, pointed at one end, subcompressed, thin; surface ornamented
by numerous small, concentric ribs, abrupt on the upper side, and sloping downward on the side
towards the base; beaks minute, placed in advance of middle; anterior end narrow, subacuminate-
concave above; posterior end broadly rounded; lunule long, narrow, deeply impressed, smooth; hinge
with prominent cup-shaped cartilage-pit, with about twelve sharp teeth in front, and about fifty
behind; pallial sinus large, deep and rounded.
Dimensions. — Long. 64 mm.: alt. 32 mm.; diam. 10.5 mm.; umbo to anterior end 22 mm.,
to posterior end 44 mm.
The largest of the Nuculidfe found in these deposits; easily distinguishable by
its size, peculiar shape, and teeth. One imperfect specimen measured S3 mm. in
length. The Miocene form (Y. impressaj is much smaller and less compressed.
Specimens identified by Dr. Dall.
Rare in upper San Pedro series of San Pedro; three specimens. Found also
in Pleistocene of Spanish Bight, San Diego, and Barlow's ranch, Ventura.
Living. — Santa Cruz to San Diego (Cooper): Half Moon Bay (Arnold).
Pleistocene. — San Pedro (Cooper; Arnold): San Diego; Ventura (Arnold).
f?J Pliocene. — San Fernando (Cooper).
18. Yoldia scissurata Dall.
Plate XVII, Fig. 13.
Yo/dia scissurata Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 4, 1898, p. 595.
Yoldia arctica Brod. & Sby., Zool. Jour., 1829 (not of Gray, Parry's Voyage App., 1824, fide
Dall, Trans. Wagner Inst. Sci., Vol. Ill, 1898, p. 595).
Shell rather small, oval, compressed, very thin, translucent, only slightly narrowed posteriorly;
umbones minute, slightly anterior to middle, the anterior margin is evenly convex; a thin lamina
runs along the anterior margin from the umbo to the end of the shell; a much narrower one also
100 CALIFORNIA ACADEMY OF SCIENCES.
occurs on the posterior margin; surface sculptured concentrically as in }'. cooperi except that this
incised sculpture is not in harmony with the incremental lines; hinge and teeth similar to Y. cooperi.
Dime7isio7is.- — Long. 20.4 mm.; alt. 10 mm.; diam. 4 mm. ; from umbo to anteriorend 9 mm. ;
to posterior end 12 mm.
This delicate little shell resembles Y. cooptri \\\ many respects, but is easily
distinguishable by its smaller size, more delicate shell, the peculiar way in which the
sculpture crosses the incremental lines, and by its relatively broader anterior end.
Probably the Y. amygdala Yal. reported by Cooper (7tli Ann. Rept. Cal. St. Min.,
1888, p. 270) as occurring at Deadman Island is Y. scissurata Dall. Specimens
identified by Dr. Dall.
Three specimens from lower San Pedro series of Deadman Island; lare.
Specimens of Y. scissurata in the State Museum collection of fossils at Berkeley are
labeled Y. amygdnla. The specimen figured is from the lower San Pedro series at
Deadman Island, and is now in the collection of Delos Arnold.
Living. — Puget Sound (Carpenter).
Pleistocene. — San Pedro (Arnold.
Superfamily ARCACEA.
Family VII. ARCID.E.
Subfamily PECTUNCULlNyE.
Genus Glycy maris Da Costa.
Shell orbicular, nearly equilateral, smooth or radiately striated; umbones central, divided by
a striated ligamental area; hinge with a semicircular row of transverse teeth; adductors subequal;
pallial line simple; margins crenated inside.
Type, Area glycymeris Linn.
19. Glycymeris barbarensis Conrad.
Plate XVIII, Fic. 9.
Axi7tea barbarensis Con., Pac. R. R. Rept., Vol. VI, 1857, p. 71, PI. Ill, fig. 11; Vol. VII, 1S57, p.
194, PI. VI, fig. 3.
Axinea intermedia (not of Brod. ; not of Carpenter, Brit. Assn. Rept., i86j, p. 644), of Cooper,
in part, 7th Ann. Rept. Cal. St. Min., 1888, p. 230 (not of Keep, West Coast Shells, 1892,
p. 169; not of Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 192; not of Dall,
Trans. Wagner Inst. Sci., Vol. Ill, Part 4, 1898, p. 608.
Shell of medium size, convex, thick, subcircular, with angular aspect at umbones caused by
the anterior dorsal margin being nearly straight; posterior end rounded; anterior end angular; sur-
face area between umbones and interior as in G. septentrionalis.
Dimensions. — Long. 33.3 mm.; alt. 32 mm.; diam. 22 mm.
Distinguishable from 0. septentrionaliii. by wider, more trigonal shell and angular
AENOLD— THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 101
aspect of anterior extremity. Thi.s fossil form of Conrad's is separated from the living
O. intermedia by Dr. Dall. Specimens identified by Dr. Dall.
Rare in upper San Pedro series of San Pedro, Los Cerritos, Deadman Island
and Crawfish George's. Found also in the Pleistocene of Pacific Beach, San Diego.
The specimen figured is from the upper San Pedro series at San Pedro, and is now
in the collection of Delos Arnold.
Pleistocene. — Santa Barbara (Conrad): San Pedro (Arnold): San Diego
(Arnold).
20. Glycymeris septentrionalis MUUemhrf.
Plate XVIII, Fm. 10.
Pechinculus septenbionalis Midd., Carpenter, Brit. Assn. Rept., 1856, p. 219.
Shell of medium size, nearly circular, conve.x, thick; umbones central, not prominent; sur-
face sculptured with rather faint ridges of growth and radiating grooves, which are more or less
interrupted by the ridges; triangular ligamental area between umbones divaricately striated; hinge
with a semicircular row of transverse teeth; muscle impressions subequal; interior of margin
crenulated.
Dimensions. — Long. 30 mm.; alt. 32.2 mm.; diam. 22 mm.
Distinguishable from O. harharens.h by its evenly rounded outline. Differs
from Carpenter's living P. septentrionalis var. subobsoleta by having larger, thicker
shell, greater convexity, and more pronounced sculpture. Specimens identified by
Dr. Dall.
Rare in upper San Pedro series of San Pedro, Los Cerritos, Crawfish George's,
Deadman Island and Long Beach. The specimen figured is from the upper San
Pedro series at San Pedro, and is now in the collection of Delos Arnold.
Living. — Ukamok Island, Alaska coast (Carpenter).
Pleistocene. — San Pedro (Arnold).
Subfamily ARGIN^E.
Genus Area (Linne) Lamarck.
Shell oblong, subquadrangular, gaping anteriorly or inferiorly; hinge linear, straight, formed
of a large number of small pectinated teeth; ligament external, inserted upon a lozenge-shaped area
between the beaks, beaks high, rather wide apart; muscular impressions very distinct; pallial im-
pression entire.
Type, Area nom Linne.
21. Area labiata Son-erhij.
Plate SVIII, Fig. 4.
Area labiata Sby., Carpenter, Brit. Assn. Rept., 1856, pp. 310, 363.
Shell of medium size and thickness, arculate below, straight above, with small but promi-
nent presocoelous beaks; anterior extremity evenly rounded; posterior extremity angular near base,
a rather prominent convex angle running from beak to lower portion of the posterior extremity; right
102 CALIFORNIA ACADEMY OF SCIENCES.
valve with twenty-eight square topped, rather narrow, radial ridges, separated by shghtly narrower
interspaces; cardinal area triangular, broad, faintly sculptured with parallel lines transverse to hinge
line; two nearly equal series of teeth, crowded in middle, becoming slightly oblique and further
separated at the distal ends; margins serrate.
Dimensions. — Long. 28 mm.; alt. 26 mm.; distance between dorsal and ventral margins
20 mm.; umbo to anterior extremity 11 mm.; to posterior e.xtremity 17 mm.
'ibis is the only Area so far reported from the Pleistocene of the Pacific Coast.
It has been reported by Carpenter as being one of the few species common to both
the West Indian and Pacific (Panama) faunas. This species and Hippomjx antiqua-
tus, which Carpenter considers equal to H. miirula of the West Indian fauna, are the
only two species which occur in the Pleistocene of San Pedro and the living fauna of
the West Indies. These two species offer no proof of a close water connection be-
tween these two regions during Pleistocene time, for the occurrence in both regions
of these two species is merely accidental, or a coincidence. The specimen described
was identified by Dr. Dall.
Rare in the upper San Pedro series of San Petlro; two specimens, a right and
a left valve. The specimen figured is from the upper San Pedro serie.< at San Pedro,
and is now in the collection of Delos Arnold.
Lioing. — Gulf of California; Central America; West Indies (Carpenter).
Pleistocene. — San Pedro (Arnold).
Superfamily OSTRACEA.
Family VIII. OSTREID.E.
Genus Ostrea (Linnf) Lamarck.
Shell irregular, attached by the left valve; upper valve flat or concave, often plain; lower
convex, often plaited or foliaceous, and with a prominent beak; ligamental cavity triangular or
elongated; hinge toothless, structure subnacreous, laminated, with a prismatic-cellular substance
between the margins of the laminte.
Type, Ostrea edulis Linne.
22. Ostrea lurida Carpenter.
Ostrea lurida Cpr., Brit. Assn. Rept., 1S63, p. 645; Jour, de Conch., Vol. XII, 1865, p. 137. Gabb,
Pal. Cal., Vol. II, i86g, p. 106. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 256. Keep,
West Coast Shells, p. 164, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 193.
Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 4, 1898, p. 687.
Shell of medium size, irregular, suborbicular, ellipsoidal, or elongated; surface laminated and
sometimes irregularly plaited; beak prominent; hinge toothless.
Di9netisions. — Long. 35 mm.; alt. 50 mm.
Grades into two varieties, expansa Cpr., which is nearly circular, and rafoides
Cpr., which is of a retldish hue on the interior. Specimen identified by Dr. Dall.
AKNOLD — THE PALEONTOLOGY AND STKATIGRAPHY OF SAN PEDRO. 103
Typical form exceedingly common in the upper San Pedro series of San
Pedro, Los Cerritos and Long Beach; rare in the lower San Pedro series of Dead man
Island and San Pedro. Fonnd also in Pleistocene of Twenty-sixth street and Pacific
Beach, San Diego.
Living. — Straits of Fuca to San Diego (Cooper).
Pleistocene. — Benicia, Solano County; San Diego (Cooper; Arnold): San
Pedro (Arnold).
Superfamily PECTINACEA.
Family IX. PECTINID.E.
Genus Pecten Midler.
Shell suborbicular, regular, resting on the right valve, usually ornamented with radiating
ribs; beaks approximate, eared; anterior ears most prominent; posterior side a little oblique; right
valve most convex, with a notch below the front ear; hinge margins straight, united by a narrow
ligament; cartilage internal, in a central pit; adductor impression double, obscure; pedal impression
only in the left valve, or obsolete.
Type, Ostrea maximd Linne.
Subgenus Pecten .s. s.
Right valve moderately inflated, left valve flattish; sculpture of strong ribs with radial stri-
ation, more or less roughened by simple concentric lamellation or incremental sculpture; ears
subequal.
Type, Pecten mn.ciinus Linne.
[S. B.] Pecten (Pecten) bellus Conrad.
Plate XXI, Fics. 1 and 2.
Janira bella Conrad, Proc. Acad. Nat. Sci. Phila., 1S56, p. 312; Pac. R. R. Rept., Vol. VI, 1857,
p. 71, PI. Ill, fig. 16. Gabb, Pal. Cal., Vol. II, 1S69, PI. XVI, fig. 20. Cooper, 7th Ann.
Rept. Cal. St. Min., 1888, p. 244; not P. bellis McCoy {teste Dall).
Pecten (Pecten) hemphitli Dai.1., Trans. Wagner Inst. Sci., Vol. Ill, Part 4, 1898, p, 706 (pars. ?).
Pecten (Pecten) bet/us Con., Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 4, 1898, p. 704.
Shell large, thin, inequivalve, elegantly, radiately ribbed. Left (upper) valve slightly convex,
the point of greatest convexity being generally about one-fourth the distance from the apex toward
the ventral margin; between this point of greatest convexity and the apex there is a deeply depressed
area, the depression generally not affecting the two outer ribs on each side, which inclose the depres-
sion on the sides; surface of left valve ornamented by thirteen or fourteen prominent, flat-topped,
sometimes faintly bicarinated, radiating ribs, which have flat, sloping sides; these ribs become broader,
less elevated and less sharply angulated near the periphery in the adult; interspaces slightly wider
than the tops of the ribs, with slightly rounded bottoms; whole surface of left disk covered with fine,
sharp, concentric, regular lamelkt; ears rather small, subequal, slightly concave, finely concentrically
lamellated, separated from the disk by an impressed line. Right (lower) valve prominently convex,
the point of greatest convexity being about one-third the distance from the apex to the ventral margin
of the disk; the umbo in this valve curves sharply and meets the plane of the ears at an angle of
104 CALIFOKNIA ACADEMY OF SCIENCES.
about ninety degrees; surface of right valve ornamented by fourteen or fifteen prominent, nearly flat-
topped, square, radiating ribs, some of them with one or two longitudinal obsolete lines; the ribs
become somewhat less elevated and the sides more sloping as the periphery is approached in the
adult; surface of right disk ornamented with close, fine, squamosa, concentric wrinkles; ears subequal,
arched, covered with crowded, elevated lamelke; byssal notch small.
Dimensions. — Alt. 80 mm.; lat. 108 mm.; diam. 32 mm.; length of hinge-line, 45 mm.
Found in the Pliocene at tSanta Barbara, California (Coniad, Gabb, Yates
Cooper, Arnold).
The description, measurements, and figures are of Gabb's type specimen of
Janira bella (No. 960, Collection Academy Natural Sciences, Philadelphia), which
was kindly loaned to the writer by Professor H. A. Pilsbry, Curator of Mollusca.
F. stearnsii and P. diegeiisis are distinguishable from P. bellus by the more
numerous (25 or 28 in the first, 20 or 22 in the second), narrower, sharper defined,
perpendicular-sided, radiating ribs on the right valve, and by evenly rounded, promi-
nently and evenly lamellated ribs of the left valve. /'. hemphilli is distinguishable
from P. hellua by its smaller size; by having on the right valve more numerous (15
or 16 in the former), round-topped, narrower, nearly perpendicular-sided, radiating
ribs, which retain their prominence for their entire length, and by the less convexity
of the disk, more numerous, narrower and more elevated radiating ribs of the left
valve. P. hemphilli has the .same depression below the apex in the left valve, but
the less degree of convexity of the rest of the disk lessens the prominence of the de-
pression, which is so marked in most specimens of P. bellns. P. deutains is dis-
tinguishable from P. bellns by its smaller size, greater convexity of right valve, greater
concavity of left valve, greater number of ribs, and by the auxiliary ribs in the
left valve.
After a careful comparison of a large series of P. bellus with Conrad's descrip-
tion and figure and Gabb's figure and type specimen, the writer has no hesitancy in
adopting the synonymy given at the beginning of this article. Dall is of the opinion
that Conrad's species and that of Gabb are different. This idea was probably caused
by the exaggeration of the bicarination of the ribs in Conrad's figure. Several of
the specimens of P. bellus examined by the writer show this bicarination to a greater
or less degree, although as a rule the ribs are nearly smooth-topped. A large series
of /■'. bellus and P. hemi^hilli show the differences enumerated in a previous paragraph
to be constant for the adults. The young of both species up to an altitude of twenty
millimeters are nearly identical in appearance.
23. Pecten (Pecten) dentatus Soirerbi/.
Plate XII, Figs. 1 and In.
Pecten dentatus Sbv., Thes. Conch., Vol. I, p. 39, PI. XV, figs. 105, 106. Dall, Trans. Wagner
Ins. Sci., Vol. Ill, Part 4, 1892, p. 707.
Vola dentata Sby., H. &. A. Ad.vms, Gen. Rec. Moll.
/anira dentata Sby. {=J. excavata, Val., 7?af^ Carpenter, Brit. Assn. Rept., 1863, p. 654). Gabb,
Pal. Cal., Vol. II, 1869, p. 104. Cooper, -th Ann. Rept. Cal. St. Min., 1S88, p. 244 (==/'.
stearnsii Dall, in part).
ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 105
Shell of medium size, subcircular, inequivalve, concavo-convex, rather thin; right valve gib-
bous, with twenty smooth, rounded, only moderately convex ribs, separated by very faintly channeled,
narrow interspaces; surface smooth except for fine, undulating lines of growth; ears on this valve con-
vexly bent, and separated from the disk by a deep groove; anterior ear with small byssal notch,
obsoletely, radiately ribbed, and with fine incremental lines; posterior ear similar except that it lacks
the notch; left valve concave, with nineteen or twenty prominent squarish ribs, which are separated
by deep channeled interspaces of equal width with the ribs; a faint rounded rib runs along the middle
of each of the interspaces; surface with fine undulating incremental lines; ears of this valve concave,
with obsolete radiating ridges and fine lines of growth.
Dimensions. — Long. 70 mm.; alt. 67 mm.; diam. 25 mm.; hinge 35 mm.
Distiugaishable from P. liemphilli Dall by greater convexity of the right
valve, and by the greater number of ribs, P. hempldUi having only about fifteen ribs;
distinguishable from P. stearnsii and P. dlegensis Dall by greater convexity of right
valve, low rounded ribs rather than square ones on this valve; and by square ribs,
between which are faint rounded riblets, rather than sharply rounded ribs on the left
valve. P. dentatus is of the same shape as the Japanese species P. laqueatus Sby.,
which has fewer, but squarer, broader ribs on the right valve. This last species has
been reported from the Tertiary of Japan by Dr. Brauns in his Geology of the
Environs of Tokio.' "P. laqueatus has been erroneously cited by Reeve from Cali-
fornia" (Dall).
An almost perfect right valve of this beautiful southern shell was found in the
upper San Pedro series of San Pedro. It differs from a living specimen from the
Gulf of California by having twenty rather than twenty-three ribs, and by having
slightly less convex ribs and wider interspaces. In degree of convexity and in its
ears it agrees exactly with the living shell. The specimen was identified by Dr. Dall.
Cooper has mistaken the flat valve of P. dearnsii for this species. A specimen
in the State Museum collection at the University of California, Berkeley, labeled
"Janira dentata Sby., San Pedro, Quaternary," is a P. stearnsii from the Pliocene of
Deadman Island.
The specimen figured is a living shell from the Gulf of California, and is now
in the collection of the Department of Geology, Leland Stanford Junior University.
Living. — Gulf of California (Carpenter; Button).
Pleistocene. — Santa Barbara to San Diego (Cooper): San Pedro (Arnold).
Pliocene. — San Diego well (Cooper) — (probably P. hemphilli).
[S. D.] Pecten (Pecten) hemphilli Dall.
Peden hetnphilli Dall. , Proc. U. S. Nat. Mus., Vol. I, 1879, p. 15. Cooper, 7th Ann. Rept. Cal.
St. Min., 1888, p. 257. Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 4, 1898, p. 706. Not
Janira bella CoN., Pac. R. R. Rept., Vol. VI, 1857, p. 71, PI. Ill, fig. 16; nor Gabb, Pal.
Cal., Vol. II, 1869, PI. XVI, fig. 20.
Shell of medium size, thin, inequivalve. Upper (left) valve flat or slightly concave, with a
concave depression between middle of valve and umbo; surface of this valve sculptured by sixteen
> Mem. Univ. Tokio, No. 4, 1881, p. 48, PI. VII, fig. 31.
( 14 I November 3, 1902.
106 CALIFORNIA ACADEMY OF SCIENCES.
or seventeen very prominent, rather narrow radiating ribs, which are nearly fiat-topped and have
nearly perpendicular sides; interspaces wider than ribs, with rounding bottoms; fine incremental
lamellae cover the surface of this valve; ears square-cornered and concave, covered with incremental
lamelke. Lower (right) valve convex, most apparent between middle of valve and umbo; sculptured
by sixteen prominent squarish ribs, which are similar to those on the upper valve, except that they
are slightly broader and have a more rounded top; whole surface sculptured by very fine incremental
lines; ears similar to those of upper valve except convex, and the right one having three or four radi-
ating ridges and a small byssal notch.
Dimerisions. — Long. 63 mm.; alt. 56 mm.; diam. 15 mm.; hinge-line 28 mm.
This species is readily distinguishable from P. stearnsii and P. diegensis by its
smaller size, greater convexity of lower valve, and fewer ribs. Distinguishable from
P. bellus by smaller size, flat or concave upper valve, and narrow, more elevated and
prominent radiating ribs. Common in the upj^er horizon of the Pliocene at Pacific
Beach, and also in the strata exposed on Tenth Street, near Russ School, San Diego.
Pliocene. — Pacific Beach and Buss School, San Diego (Hemphill; Dall;
Arnold).
24. Pecten (Pecten) stearnsii Dull.
Plate XII, Fin. 3.
Pedoi stearyisii Dall., Proc. U. S. Nat. Mus., Vol. I, 1878, p. 14; Trans. Wagner Inst. Sci., Vol.
Ill, Part 4, 1898, p. 706, PI. XXVI, fig. 5.
/antra dentata Sby. (?), Gabb, Pal. Cal., Vol. II, 1S69, p. 104 (in part). Cooper, 7th Ann. Rept.
Cal. St. Min., 1888, p. 244 (in part).
Shell of medium size, subcircular, inequivalve, concavo-convex, thin; right valve slightly
convex, with about twenty-six regular, even, square ribs, separated by channeled interspaces some-
what narrower than the ribs ; the top surface of each rib is flattened with a broad, shallow groove in
the middle, with one or two faint riblets on each side of the groove; whole surface covered with
concentric lamelte which are much finer and about twice as crowded as those of the left valve; left
valve flattened or concave, with about twenty-four regularly rounded, vaulted, even ribs, separated
by slightly wider channeled interspaces; the whole surface covered with fine, sharp, concentric,
regular lamellae, a little looped backward over the tops of the ridge; ears of this valve concave, with
obsolete radiating ridges, and fine, concentric lamellae; ears of right valve subequal, arched, covered
with crowded, elevated lamellae; byssal notch very small.
Dimensions. — Long. 71 mm.; alt. 62 mm.; diam. 14 mm ; hinge 25 mm.
"This is the Pliocene precursor of P. diegensis Dall (Plate XII, fig. 5), {P.
floridus of Hinds, not of Gmelin) from which it differs by having five or six more
ribs, which, in the adult, have a conspicuous median sulcus." (Dall.) Mrs. Old-
royd has eight P. diegensis which have been hauled up in the fishermen's nets at San
Pedro; two of these are over six inches in diameter and are exceptionally high
colored for this species.
Two imperfect left valves from the Pliocene of Deadman Island. The figure
is of a left valve from the Pliocene of San Diego. Specimens identified by Dr. Dall.
Pliocene. — San Pedro (Arnold) : San Diego (Pacific Beach, lower horizon),
(Dall; Hamlin; Hemphill; Arnold).
AENOLD— THE PALEONTOLOGY AND STRATIGKAPHY OF SAN PEDKO. 107
Subgenus Chlamys Bolten.
Valves moderately inflated, subequal, in general similar (except in color); sculpture of
radial ribbing with or without Camptoyiectes striation, with or without an imbricate surface layer;
frequently spinose on the ridges; ears often discrepant, the posterior smaller.
Type, Pecten islandicus (Miiller).
Section Patinopeden Dall.
Valves with small ribs, flat on the right valve and sometimes dichotomous; smaller and
more rounded on the left valve; concentric sculpture inconspicuous; radial stride absent or
obsolete; ears subequal ; valves nearly equilateral.
T3'pe, Pecten cauiinus (Gld.).
25. Pecten (Patinopecten) caurinus Gould.
Plate XIII, Fig. 6.
Peclen caurinus Gld., Proc. Bost. Soc. Nat. Hist., Vol. Ill, 1850, p. 345; Wilkes E.xpl. Exped.,
Vol. XII, 1852, p. 458, fig. 569. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892,
p. 193; T=: p. yessoeiisis Cpr., (non Jay, 1856); ^= P. propatulus Carpenter (non
Conrad, 1849) {Jide Dall., Trans. Wagner Inst. Sci., Vol. Ill, Part 4, 1898, p. 710).
Amusium cauriuum Gld., Carpenter, Brit. Assn. Rept. , 1863, p. 645. Cooper, 7th Ann. Rept.
Cal. St. Min., 1888, p. 228. Keep, West Coast Shells, p. 168, 1892.
Shell large, nearly circular, flat inequivalve, rather thin; right valve with twenty strong,
flat-topped, smooth, squarish ribs, with interspaces wider than the ribs ; left valve less conve.x than
right, with seventeen rather acutely rounded ribs, with wide, shallow interspaces ; surface of left
valve sculptured by regular, fine, undulating, concentric lines; ears not large, obliquely truncated at ends.
Dimensions. — Long, no mm.; alt. no mm. ; diam. 16 mm.; hinge 46 mm.
Tliis large, flat Pecten i.s distinguishable from the others of this genus found in
these deposits b}^ its size and shape. P. expansua Dall differs from this species by
having twenty-five to thirty dichotomous ribs. P. yessoensis from Amori, Rikonoken,
Japan, differs from P. caurinus by having a more convex shell, wider, lower, more
rounded ribs on the right valve, less prominent ribs on the left valve, and by hav-
ing larger ears, which are truncated more nearly at right angles at the ends. Pecten
jtrojMtulus Conrad is more convex and has fewer but stronger ribs and narrower
interspaces on the right valve. Specimens identified by Dr. Dall.
Common in the Pliocene of Deadman Island and Timm's Point; rarer in the
lower San Pedro series of Deadman Island and San Pedro. Also found in Pleisto-
cene on beach near bath-house and in Pliocene at Packard's Hill, Santa Barbara.
The specimen figured is from the Pliocene of Deadman Island and is now in the col-
lection of Delos Arnold.
Living. — Puget Sound (Carpenter).
Pleistocene. — Santa Barbara; San Pedro (Cooper; Arnold).
Pliocene. — Eagle Prairie, Humboldt County; San Fernando (Cooper).
108 CALIFORNIA ACADEMY OF SCIENCES.
[S. D.] Pecten (Patinopecten) expansus Dali.
Pecieti expansus Dall, Proc. U. S. Nat. Mus., Vol. I, 1879, p. 14; Trans. Wagner Inst. Sci., Vol-
III, Part 4, 1898, p. 706.
Shell large, thin, slightly convex ; outer surface of upper (left) valve marked by sixteen to
twenty sharp radiating ridges, but slightly elevated, and whose sides shade off insensibly into the
broad interspaces ; faint indications of ridges appear between the principal ones ; surface of upper
valve covered with fine, slightly raised, sharp lamellae ; lower (right) valve with twenty or thirty
dichotomous ribs, flattened above, but not sharply differentiated from the interspaces, sculptured with
fine lines of growth, with faint appearances of radiating strite ; ears rather small, and distinctly but
not strongly marked off" from the disk ; byssal notch rounded, moderately deep.
Dimensions. — Long. 140 mm.; alt. 135 mm.; diam. 32 mm.; hinge-line 65 mm.
This species is close to P. cnurinus, but may be distinguished by the dicho-
tomous ribs on the lower valve, and the faint ribs between the principal ones on the
upper. A species of Pecten near, if not identical, to P. expansus is found in the Plio-
cene near Purisiraa, Sau Mateo County, California. P. expansus is common in the
lower horizon of the Pliocene at Pacific Beach, near San Diego.
Pliocene. — Pacific Beach, San Diego (Hemphill; Dall; Hamlin; Arnold).
Section Nodipecten Dall.
Both valves convex, usually of large size and heavy ; ribs intermittently nodose, with
more or less prominent hollow nodes or buttse ; radial striation pronounced ; ears unequal, the pos-
terior smaller; the valves often more or less oblique; imbricate surface layer sometimes very marked.
Type, Pecten nodosus Linne.
26. Pecten (Nodipecten) subnodosus Soiverby.
Pecten suktiodosus Sby., Proc. Zool. Soc, 1835, p. 109. Carpenter, Brit. Assn. Rept., 1856, p. 311;
Brit. Assn. Rept., 1S63, p. 621. Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 4, 1898, p. 710.
Pec/en ijitermedius Con., Am. Jour, Conch., Vol. Ill, 1867, p. 7.
Shell large, suboval, convex; surface sculptured with numerous high, square ribs, three or
four of which are generally more prominent than the others; interspaces deeply channeled, averaging
about equal in width with the ribs; surface, including the ribs and interspaces, sculptured by fine
radiating, squamose ridges, and fine lines of growth; ears rather small, sculptured in same manner
as the disk.
Dime7isio7is. — Long. 120 mm.; alt. 125 mm.; diam. 45 mm.
This large tropical species is distinguishable by strong elevated ribs and pecu-
liar squamose, radiating ridges. Dr. Dall .says of this species: "There seems to be
little reason for separating this form from the P. nodosus of the Antilles. Both vary
through a strictly analogous series of mutations."
One-half of a large left valve was found in the upper San Pedro conglomerate
of Deadman Island by Dr. A. A. Wright, who also found a young specimen of the
same species in the upper San Pedro series of San Pedro.
Living. — Lower California to Panama (Carpenter).
Pleistocene. — San Pedro; San Diego (Arnold): Cerros Island and Lower Cali-
fornia (Dall).
ARNOLD — THE PALEONTOLOGY AND STKATIGKAPHY OF SAN PEDRO. 109
Section Chlaviys s. s.
Ribs small and numerous, imbricate or spinose; valves subequal, similar, oblique, or with
unequal ears, the posterior smaller; Ca^nptonedes striation and imbricate surface layer usually present;
shell usually solid and opaque; byssal notch and ctenolium present.
Type, Peden idandicus (Mllller).
27. Pecten (Chlamys) hastatus Soiverby.
Plate XI, Figs. 4 and 4«.
Pedeii hastatus Sby., Thes. Conch., 1843, p. 72, PL XXII, fig. 236 (not of Carpenter, Brit. Assn.
Rept., 1863, p. 645 = /". hericeus Gld.); (? not of Gabb, Pal. Cal., Vol. 11, 1869,
p. 104); (? not of Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 257). Dall, Trans.
Wagner Inst. Sci., Vol. Ill, Part 4, 1898, p. 708.
Shell similar in shape and general characteristics to P. hericeus. Left valve sculptured with
eight to ten prominent, narrow, convex, coarsely spinose, radiating ribs separated by interspaces
several times wider than the ribs; interspaces ornamented with fasciculi of small spinose ribs, which
in some cases have only the importance of spinose lines; anterior ear large, acutely pointed, with
three or four prominent, spinose, radiating ribs; right valve with eight to ten pairs of equally
prominent, coarsely spinose ribs, each pair separated from the next by deep rounded interspaces
along the bottoms of which run fine spinose lines: the members of each pair of ribs separated from
each other by interspaces about as wide as one rib, and also ornamented with spinose lines ; anterior
ear with four or five strong spinose ribs and separated from disk by deep notch; posterior ears nearly
obsolete, radiately spinose.
Dimensions. — Long. 54mm.; alt. 61 mm.; diam. 21 mm.; hinge 28 mm.
Distinguisliable from P. hericeun by the less nuraerou.s, but more prominent
and more strongly spinose radiating ribs. Dr. DalP says that Carpenter confused P.
hericeus with P. hastatus, and as Gabb and Cooper have probably used Car[)enter's
P. " hastatus " as their type, their localities for that species would come under
P. hericeus.
Mrs. Oldroyd has a beautiful pair of Pecten hastatus which was taken from a
fisherman's net at Ban Pedro. Dr. Dall identified this shell and said that it was the
first genuine P. hastatus that had ever been found at San Pedro. This species is a
northern form.
Rare in Pliocene and lower San Pedro series of Deadman Island; one speci-
men from upper San Pedro series of Crawfish George's. The specimen figured is
from the Pliocene of Deadman Island, and is now in the collection of Delos Arnold.
Found also in the Pliocene at Packard's Hill, Santa Barbara, and Pacific Beach, San
Diego; and in the Pleistocene at the bath-house, Santa Barbara.
Living. — San Pedro (Oldroyd; Raymond).
Pleistocene. — San Pedro; Santa Barbara (Arnold).
Pliocene. — San Pedro; Santa Barbara; San Diego (Arnold).
1 Trans. Wagner Inst. Sci., Vol. Ill, 1898, p. 708.
1 1 0 CALIFORNIA ACADEMY OF SCIENCES.
28. Pecten (Chlamys) hericeus Gould.
Plate XI, Fig. 2.
Pecten hericeus Gld., Proc. Bost. Soc. Nat. Hist., Vol. Ill, 1S50, p. 345; Wilkes E.xpl. E.>;ped.,
Vol. XII, 1852, p. 457, fig. 570. Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 4,
1898, p. 708.
Pecten hastatus of Carpenter, Brit. Assn. Rept., 1863, p. 645 (not of Sowerby, Thes. Conch.,
1843). ? Gabb, Pal. Cal., Vol. II, 1869, p. 104. ? Cooper, 7th Ann. Rept. Cal. St.
Min., 1888, p. 257.
Shell of medium size, triangular ovate, compressed, equivalve, thin; surface of left valve
sculptured by about fourteen to sixteen groups of fasciculated ribs, the groups being more prominent
and containing more ribs as the middle of the shell is approached; the surface of all the ribs
roughened by numerous rather small, erect, arched spines; right valve nearly the same as left;
anterior ear of left valve large, acutely pointed with seven to eight sharp, squamosely striated
radiating ribs; posterior ear nearly obsolete; ears of right valve the same e.xcept that a deep byssal
notch separates anterior ear from disk; sides of umbo rise abruptly from ears.
Dime^isions. — Long. 40 mm.; alt. 47 mm.; diam. 12 mm.; hinge 19 mm.
Thi.s species resembles P. hastatus in shape and general characteristics. In
P. hastatus there are seven to ten strong, narrow, prominent ribs, coarsely spinose,
while in P. hericeus the ribs occur in fourteen to sixteen fasciculi, each fascicle con-
sisting of three or four nearly equally prominent, finely spinose ribs, and forming a
convex ridge. Specimens identified by Dr. Dall.
Rare in Pliocene of Deadman Island. The specimen figured is fi-om that
horizon and is now in the collection of Delos Arnold. Found rarely in the Pliocene
of Pacific Beach, San Diego.
JAving. — Straits of Fuca (Gould) : ? Sitka to Santa Barbara (Cooper).
Pleistocene. — San Diego (Dall) : ? Santa Barbara to San Diego (Cooper) : San
Pedro (Arnold).
Pliocene. — San Pedro (Arnold): ? Santa Barbara; San Fernando; San Diego
well (Cooper): San Diego (Arnold).
29. Pecten (Chlamys) hericeus var. strategus Dall.
Pl.-vte XI, Fig. 5.
Pecten hericeus var. strategus Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 4, 1898, p. 709.
Shape and general te.xture same as P. hericeus. " The fasciculi of the left valve, to the
number of five to seven, with the riblets coalescent, forming large, smooth-backed, turgid ribs, with
smaller imbricate intercalary threads. The large ribs sometimes break up suddenly into the usual
small riblets near the base. The recent specimens are bright scarlet." (Dall). The right valve oi a
young from the Pleistocene of Deadman Island shows nine fasciculi, most of which seem to be made
up of two riblets which keep their individuality to the umbo, instead of coalescing; the interspaces
are slightly narrower than the fasciculi. The anterior ear of this right valve is prominent and
ornamented with six radiating ribs, and near the disk, by elevated lines of growth; byssal notch
rather deep; whole surface ornamented with minute, lattice-like scul[)ture.
Dimensions. — ^Long. 18 mm.; alt. 21 mm.; diam. 5.2 mm.; hinge 9.4 mm.
AENOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. HI
Distinguishable by the few prominent, sulcated ridges, and smooth surface,
except for minute sculpture. Specimens identified by Dr. Dall.
Two specimens from the lower 8an Pedro series of Deadman Island, one of
which is figured, and is now in the collection of Delos Arnold.
Living. — Unalaska (Dall).
Pfeis^ocene.^Alaska (Dall): San Pedro (Arnold).
30. Pecten (Chlamys) jordani, sp. nov.
Plate XII, Figs. 6 axd 7.
Shell of medium size, shape of/', hericeus, inequi valve, rather thin; right valve with twenty-
five to thirty angular, smooth-topped, imbricated ribs, which become dichotomous after reaching a
length of about 30 mm.; interspaces deeply channeled and narrower than ribs; anterior ear imper-
fectly radially ribbed with six ridges, and showing elevated, concentric, incremental lines; posterior
ear nearly obsolete, showing four ribs; byssal notch not deep; left valve shows twenty-five to thirty
narrow, convex ribs, showing imbrications only slightly; interspaces as large as ribs; after a diameter
of about 30 mm. has been reached by the shell, small riblets appear in the widening interspaces;
anterior ear shows five narrow, imbricated ridges, with wide interspaces; both valves show a tendency
to contract suddenly at the basal margin upon nearing completion of growth ; surface of both
valves covered with a minute, lattice-like sculpture, which is generally worn off on exposed portions
of the shell.
Dimensions. — Long. 42 mm.; alt. 45 mm.; diam. 15 mm.; hinge 18 mm.
Allied to F. opimtia Dall, but having fewer ribs on disk and ear, and having
dichotomous ribs after reaching a diameter of 35 mm. Distinguished from P. hericens
and P. hastaius by not having fasciculated nor spinose ribs.
Rare in Pliocene of Deadman Island and lower San Pedro series of Deadman
Island. Found also in Pliocene of Packard's Hill and Pleistocene of bath-house,
Santa Barbara.
The specimen figured is the type, which is from the Pliocene of Deadman
Island and is now in the United States National Museum.
Pleistocene. — San Pedro, Santa Barbara (Arnold).
Pliocene. — San Pedro, Santa Barbara (Arnold).
31. Pecten (Chlamys) latiauritus Conrad.
Plate XII, Figs. 2 and 2a.
Pecten latiauritus Con., Jour. Phil. Acad. Sci., Vol. VII, 1837, p. 238, PI. XVIII, fig. 9. Reeve,
Conch. Icon., PI. I, sp. 5. Sowerby, Thes. Conch., PI. I, p. 57. Carpenter, Brit.
Assn. Rept, 1863, p. 645. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 257.
Keep, West Coast Shells, p. 167, 1892. Williamson, Proc. U. S. Nat. Mus., Vol.
XV, 1892, p. 193; = P. tioiica Phil., 1844, -\- P. mesotimeris Sowerby, 1847 {fide
Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 4, 1898, p. 709.)
Shell small, suboval, inequivalve, subequilateral, compressed, thin ; surface ornamented with
from twelve to fifteen squarish, elevated, distinct ribs, with about equal, channeled interspaces; ribs
often mesially grooved; hinge line wide, the ears pointed above.
Dimensio7is. — Long. 25 mm.; alt. 23 mm.; diam. 9 mm.; hinge 20 mm.
112 CALIFORNIA ACADEMY OF SCIENCES.
This is the type form and is distinguishable by acutely pointed ears, distinct,
squarish ribs and wide shell. Specimens identified by Dr. Dall.
Common in upper San Pedro series of San Pedro, Los Cerritos, Crawfish
George's, Deadman Island, San Pedro, and Long Beach; rare in lower San Pedro
series of Deadman Island and San Pedro. Found also at Spanish Bight and Twenty-
sixth Street, San Diego. The specimen figured is from the upper San Pedro series
at San Pedro, and is now in the collection of Delos Arnold.
Living. — Santa Barbara to San Diego (Carpenter).
Pleistocene. — Santa Barbara; San Pedro (Cooper): San Pedro (Arnold): San
Pedro; San Diego (Dall): San Diego (Arnold).
32. Pecten (Chlamys) latiauritus Con., var. fragilis, var. nov.
Plate XII, Fig. 8.
Shell of same general type as P. latiauritus. More compressed and much thinner; ribs
seven to nine, very low and rounded, with shallow, rounded interspaces; surface smooth, the
concentric sculpture being nearly obsolete ; hinge long, ears sharply pointed.
Dimensions. — Long. 26 mm.; alt. 26 mm.; diam. 78 mm.; hinge 25 mm.
Distinguishable from var. jlucicolus Dall, which it resembles, by having a
longer hinge-line and pointed ears.
Rare in upper San Pedro series of San Pedro and Los Cerritos. The speci-
men figured is the type, which is from the upper San Pedro series at San Pedro, and
is now in the United States National Museum.
Pleistocene. — San Pedro (Arnold).
33. Pecten (Chlamys) latiauritus Con., var. monotimeris Con.
Plate XII, Figs. 4 and -ta.
Pecten motiotimeris Con., Jour. Phil. Acad. Sci., Vol. VII, 1837, p. 233, PI. XVIII, fig. 10. Carpenter,
Brit. Assn. Rept., 1863, p. 645. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 257.
Keep, West Coast Shells, p. 167, fig. 140, 1892.
Pecten latiauritus vav. 7no)iotimeris Coii. , Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 4, 1898, p. 709.
Shell resembling P. latiauritus, but more oblique, inflated, and markedly shorter, with
smaller ears.
Dimensions. — Long. 19 mm.; alt. 20 mm.; diam. 9 mm.
Rare in lower San Pedro series of Deadman Island and San Pedro, and in
upper San Pedro series of Los Cerritos, San Pedro, Long Beach, and Crawfish
George's. Found also in Pleistocene of Spanish Bight, San Diego, and Barlow's
ranch, Ventura. The specimen figured is from the upper San Pedro series at San
Pedro, and is now in the collection of Delos Arnold.
Living. — Santa Barbara to San Diego (Dall).
Pleistocene. — Santa Barbara; San Pedro (Dall): San Pedro; San Diego;
Ventura (Arnold).
AKNOLD— THE PALEONTOLOGY AND STKATIGKAPHY OF SAN PEDRO. 113
I
[S. D.] Pecten (Chlamys) opuntia Dull.
Pecten (Chlamys) opuntia Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 4, 1898, p. 707,
PL XXIX, fig. 6.
Shell of medium size, allied to P. hericeus var. navarchus Dall, from which it differs by its
smaller and not fasciculated radial ribs, more elongated anterior ear, more densely, radially costate
posterior ear, small size when adult, and by a tendency to be suddenly contracted at the basal margin
on the completion of growth.
Dimetisions.— Long. 32.5 mm.; alt. 35 mm.
This species is distinguishable from tlie allied species by the large number
(forty or fifty) of unfasciculated imbricated ribs, which are of about equal prominence.
Found in the Pliocene at Pacific Beach, near San Diego, and in the Pliocene
at Packard's Hill, Santa Barbara.
Pliocene. — Santa Barbara (Arnold): San Diego (Hemphill; Hamlin; Arnold).
Section Plagioctenium Dull.
Shell thin, orbicular, with subequal inflated valves, usually equilateral, with uniform, well-
marked radial, not dichotomous ribs; the concentric sculpture in looped lamellae; the ribs strong,
frequently smooth above; the submargins impressed below the subequal auricles; the valves well
inflated, with a tendency to oblique growth in the adult.
Type, Pecten ventricosus Sowerby.
34. Pecten (Plagioctenium) newsomi, sp. nov.
Plate XI, Figs. 1 and la.
Shell of medium size, ovate-triangular, compressed, equilateral, rather thin; twenty-two
stout, smooth-topped, squarish ribs, with channeled interspaces of same width as ribs ; interspaces
and sides of ribs showing sharp imbricating lines of growth; ears of left valve subequal, with subacute
corners; surface of ears radially striated, and showing sharp incremental lines.
Dimeiisions. — Long. 24 mm.; alt. 26 mm.; diam. 8 mm.; hinge 16 mm.; angle of dorsal
margins 87 degrees.
This variety is distinguishable from P. venlricosu.^ by the much smaller angle
(87 degrees) made by the dorsal margins of the disk, that of a typical P. ventricosus
being about 110 degrees. P. neivsomi is also very much less ventricose than the
latter, and has much narrower ridges, wider interspaces, and a thinner shell; distin-
guishable from P. subventricosns by much smaller angle formed by dorsal margins,
and by narrower ridges. It resembles P. subventricosns in degree of convexity. This
species is named in honor of Dr. John F. Newsom, of Leland Stanford Junior
University.
Rare in upper San Pedro series of San Pedro and Los Cei-ritos. The speci-
men figured is the type, which is from the upper San Pedro series at Los Cerritos,
and is now in the United States National Museum.
Pleistocene. — San Pedro (Arnold).
( 15 ) December 26, 1902.
114 CALIFORNIA ACADEMY OF SCIENCES.
[S. D.] Pecten (Plagioctenium) subventricosus Ball.
Peclen (Plagioctenium) subventricosus Dall, Trans. Wagner Inst. Sci. , Vol. Ill, Part 4, 1898,
p. 707, PI. XXIX, fig. 8.
"Shell of the type of P. ventricosus Sby., from which it differs by being smaller and less
tumid, less expanded laterally, with the ribs rounded, instead of flattened, above, and with narrow
interspaces; the tops of the ribs smooth, the sides with a dense fringe of concentriclamellae." (Dall).
Dimensions. — Long. 65 mm.; alt. 65 mm.; diam. 24 mm.
Several specimeus of tliis sjiecies were found in the Pliocene of Pacific Beach,
near San Diego.
Pliocene. — Ventura County (Bovver.s): San Diego (Hemphill; Stearns; Arnold).
35. Pecten (Plagioctenium) ventricosus Sowerby.
Plate XI, Fics. 3, 3a, 6 and (in.
PecteJi ventricosus Sby., Thes. Conch., Pecten, 1843, p. 51, PL XII, figs. 18, 19. Gabb, Pal Cal.,
Vol. II, 1869, p. 104. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 258. ^ P. ticmidus
Sby., 1835 (not of Turt., 1S22, nor of Zeiten, 1830) = P. circularis Sby. {ex parte)
= P. inca d'Orb., 1847 ^fi'^^ Dall., Trans. Wagner Inst. Sci., Vol. Ill, Part 4, 1S98,
p. 710).
Shell thin, orbicular, with subequal inflated valves which are subequilateral ; uniformly
radiately ribbed; about twenty-two strong, angular, even ribs separated by narrow interspaces; the
whole surface covered with fine, sharp, concentric, looped lamellce, which exhibits the oblique growth
in adult shells; ears moderately small, nearly equilateral in left valve; byssal notch prominent; surface
of ears ornamented with fine concentric lamelke of growth, and sometimes with radiating ridges.
Dimensions. — Long. 59 mm.; alt. 50 mm.; diam. 32 mm.; hinge 31 mm.; angle of dorsal
margin 1 10 degrees.
P. cequisulcaius Carpenter resembles this species very closely, but is thinner
and flatter and has narrower ribs. Probably all the Pleistocene forms would come
under the head of P. ventr'icosua, but many of them have been labeled P. /.(^qui-
sulcatus. Specimens identified by Dr. Dall.
Figures 6 and 6«, Plate XI, represent a shell which was found in the
upper San Pedro series at San Pedro, and which is probably a variety of P.
ventricosus.
Very common in the upper San Pedro series of San Pedro, Long Beach, Los
Cerritos, Crawfish George's, and Deadman Island. Found also in Pleistocene on Old
Mission ditch, north of Ventura, and in the Pleistocene at Tweuty-sixth Street. Sau
Diego. The specimen figured is from the upper San Pedro series at Sau Pedro, and
is now in the collection of Delos Arnold.
Lioing. — Santa Barbara to west tropical America (Dall).
Pleistocene. — San Pedro; San Diego; Lower California (Hemi'hill; Stearns;
Orcutt; and Cooper): San Pedro; Ventura; Sau Diego (Arnold).
ARNOLD — THE PALEONTOLOGY AND STEATIGRAPHY OF SAN PEDRO 115
Subgenus Hinnites Defrance.
Shell (up to advanced youth) a typical Ck/aniys. later becoming- sessile and irregular, in
which stage the resilial pit is elongated and the cardinal margin develops an obscure area.
Type, HinniteH cortezl Defr.
36. Pecten (Hinnites) giganteus Gray.
Hinnites giganteus Gray, Ann. Phil., 1826, p. 103. Carpenter, Brit. Assn. Rept. . 1863, p. 675.
Gabb, Pal. Gal., Vol. II, 1869, p. 105. Cooper, 7th Ann. Rept. Gal. St. Min., 1888.
p. 243. Keep, West Goast Shells, p. 165, fig. 138, 1892. Williamson, Proc. U. S.
Nat. Mus., Vol. XV, 1892, p. 193. -f H. poulsoni Conr. ^ (?) //. crassus GoN.,
{Jide Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 4, 1898, p. 711)
Shell large, oval, irregular, inequivalve, subequilateral; surface sculptured by about seventeen
irregular, squamose, rounded, prominent radiating ridges, with two or three minor ones between each
pair of the large ones.
Dimensions. — Long. 65 mm.; alt. 65 mm.; diam. 25 mm.
Adult.s distinguishable from Pecten on account of distortion caused by attach-
ment to some object (hiring the later stages of growth. The young, unattached shells
of this species much resemble the young of P. hasfalus. but are distinguishable from
this species by a less spinose growth on the ribs, and also in having a much
heavier shell.
Rare in upper San Pedro series of San Pedro, Los Cerritos, Crawfish George's,
and Deadman Island; a few specimens from the lower San Pedro series of San Pedro.
Living. — Straits of Fuca to San Diego (Cooper).
Pleistocene. — Santa Barbara to San Diego (Cooper): San Pedro (Arnold).
Pliocene. — Santa Rosa Island; Ventura County; Los Angeles County (Cooper).
Family X. LIMlDyE.
Genus Lima {Britgiiin-e) Cnvier.
Shell equivalve, compressed, obliquely oval; anterior side straight, gaping, posterior
rounded, usually close; umbones apart, eared; valves white, smooth, punctate-striate, or radiately
ribbed and imbricated ; there is usually a thin, brownish epidermis ; hinge-area triangular, cartilage
pit central ; adductor impression lateral, large, double ; pedal scars, two, small.
Lima squamosa Lam. is a characteristic species.
Subgenus Lima .s. .s.
Hinge edentulous; valves gaping, inequilateral.
Section Mantellum Adams
Submargins not impressed.
Type, Liina hiaiis Gmel.
IIG CALIFORNIA ACADEMY OF SCIENCES.
37. Lima (Mantellum) dehiscens Conrad.
Lima de/itscens Con., ]our. Phil. Acad. Sci., Vol. VII, 1837, p. 247, PL XIX, figf. 7. Cooper, 7th
Ann. Rept. Cal. St. Min., 1888, p. 245. Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part4,
1898, p. 769.
Lima orieiiialis (not of Ad. & RvE.) of Carpenter, Brit. Assn. Rept., 1863, p. 645. Keep, West
Coast Shells, p. 168, fig. 142, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV,
1892, p. 193.
Shell equivalve, compressed, obliquely oval, thin, white; anterior side straight; posterior
rounded ; umbones eared, posterior ears acutely pointed ; surface smooth, radiately striate with fine
grooves; hinge-area long, narrow, triangular; cartilage pit central, prominent; margin finely
crenulated.
Ditnensions. — Long. 13 mm. ; alt. 18.5 mm. ; diam. 8 mm.
Looks like an obliquely deformed Pecten. Specimen identified by Dr. Dall.
Rare in lower San Pedro series of Deadman Island; one specimen collected
by Mi-s. Oldroyd.
Living. — Monterey to San Diego (Cooper): Santa Catalina Island (Arnold).
Pleido'cene. — San Pedro (Mrs. Oldroyd).
Pliocene. — Santa Barbara (Cooper).
Superfamily ANOMIACEA.
Family XL ANOMIID.E.
Genus Pododesmus Philippi.
Shell suborbicular, very variable, translucent and slightly pearly within ; attached by a plug
passing through a hole or notch in the right valve ; a single conspicuous byssal scar on the disk ;
valves radiately grooved ; hinge unarmed.
Pododesmus rudis Brod. is a characteristic species.
Section Monia Gray.
Adult hole or foramen large.
Pododesmus macliroscTiisma Deshayes is a characteristic species.
38. Pododesmus (Monia) macroschisma Deshayes.
Anomia macrosc/iisma Desh., Reeve, Zool. Soc. Cuvierienne, 1S39, p. 359. Mag. Zool., 1841, PI.
XXXIV. MiDDENDORF, Beitr. Mai. Ross,, Bd. Ill, 1849, p. 6. Philippi, Abbild.
beschr. Conch., 1850, p. 132, PL I, fig. 4.
Placunanomia viacroschisma Desh., Gray, Proc. Zool. Soc, 1849, p. 121. Cat. Anam. Brit. Mus.,
1850, p. 12. Carpenter, Brit. Assn. Rept., 1863, p, 646. Tryon, Syst. Conch.,
Vol. Ill, p. 294, PL CXXXI, fig. 76, 1884. Cooper, 7th Ann. Repi. Cal. St. Min.,
1888, p. 260. Keep, West Coast Shells, 1892, p. 163, fig. 137.
Placunajiomia {Monia) macroschisma Desh., Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892,
P- 194- ,
Pododesmus {Monia^ mactoscliisma Desh. ^Placunanomia ccpio Gray ^= Placitnanomia alope
Gray, {fide Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 4, 1898, p. 780).
ARNOLD— THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 117
" Shell adherent, subequivalve, irregular, flattened ; hinge with two thick, divergent, elongated
lamella in the inferior, corresponding with two long pits in the upper valve; upper valve with only
two muscular impressions; the pedal scar radiately striated"; surface with incremental laminse and
sometimes radial ridges.
Part of the above description was taken from Tryon. This species resembles
Anomin lampe, but may be distinguished by its greater size and fewer muscle-impres-
sions. Specimen identified by Dr. Dall.
Rare in the upper San Pedro series of San Pedro, Crawfish George's, and
Deadman Island. Found also in the Pleistocene of the bluff west of the bath-house,
at Santa Barbara.
Living. — Unalaska to San Diego; Japan (Cooper).
Pleistocene. — Santa Barbara to San Diego (Cooper): San Pedro (Arnold):
California; Oregon; Alaska (Dall): Santa Barbara (Arnold).
Pliocene. — San Diego well (Dall)^
2Iiocene. — Sooke, Vancouver Island (Newcombe).
Genus Anomia Linne.
Shell suborbicular, translucent, attached by a plug passing through a hole or notch in the
right valve ; upper valve convex, smooth, lamellar, or striated ; two byssal scars on the disk, main
byssal scar largest; foramen open, ample; hinge unarmed.
Anomia ejyhijjpium Linne is a characteristic species.
39. Anomia lampe Gray.
Anomia lampe Gray, Proc. Zool. Soc, 1849, p. 114. Carpenter, Brit. Assn. Rept., 1863, p. 646.
Gabb, Pal. Cal, Vol. II, 1S69, p. 106. Cooper, 7th Ann. Rept. Cal. St. Min., 18S8,
p. 229. Keep, West Coast Shells, p. 163, 1892. Williamson, Proc. U. S. Nat. Mus.,
Vol. XV, 1892, p. 194. Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 4, 1898, p. 785.
Shell of medium size, suborbicular, thin, translucent and slightly pearly within; surface of
left valve sculptured with fine, irregular, concentric lamellar lines and several prominent, irregular,
rounded, radiating ridges; interior of this valve with submarginal cartilage pit and four muscular
impressions; right or lower valve concave, with a deep rounded notch in front of the cartilage process.
Dimensions. — Long, and alt. 48 mm.; diam. 9 mm.
This species is variable both in regard to its shape and its sculpture, but is
easily distinguisliable by the thin, lamellar, translucent shell. Distinguishable from
A. limatula Dall by its smaller size and radial ridges. Specimens identified by
Dr. Dall.
Common in the upper San Pedro series of San Pedro, Los Cerritos, Long
Beach, and Crawfish George's; rare in the lower San Pedro series of Deadman Island
118 CALIFORNIA ACADEMY OP SCIENCES.
and San Pedro. Found also in tlie Pleistocene at Barlow's ranch, Ventura, and in
tlie Pleistocene of Spanish Bight and Pacific Beach, San Diego.
Living. — Monterey to Mexico (Cooper).
Pleistocene. — San Pedro (.Cooper; Ai'nold): Ventura; San Diego (Arnold).
[S. D.] Anomia limatula Dull.
Anomia limahda Dall, Proc. U. S. Nat. Mu.s., Vol. I, 1879, p. 15. Trans. Wagner Inst. Sci., Vol.
Ill, Part 4, 1898, p. 785, PI. XXXV, fig. 19.
Shell large, thin, irregular, with a rather thickened hinge-line; external surface rough, like
fiesh fractured china-ware ; surface devoid of all normal radial sculpture, and still retaining on its
yellowish valves traces of dark purple, irregularly radial blotches. The calcareous plug of this
species is peculiar, being hollow, and the cylinder incomplete on one side.
Distinguishahle from A. lampe and Pododesmiis macroschisma b}' its lack of
radial sculpture. Reported in the Pleistocene of San Pedro by Stearns.
Pleistocene. — San Pedro (Stearns): Ventura County, eight miles inland and
two hundred feet elevation above sea-level (Bowers): Si)anish Bight and Coronado
Beach, San Diego (Hemphill; Stearns): Twenty-sixth Street, San Diego (Hemphill;
Arnold).
Superfamily MYTILACEA.
Family XII. MYTILID.T:.
Genus Mytilus (Linnf) Bolten.
Shell wedge-shaped, rounded behind; umbones terminal, pointed ; hinge-teeth minute or
obsolete; pedal muscular impressions two in each valve, small, simple, close to the adductors.
Mytilus smaragdinns Chemn. is a characteristic species.
Section Mytilus .s. .s.
Surface with chiefly concentric sculpture, or smooth.
Type, Mytilus eduHs Linnc.
40. Mytilus edulis Linne.
Mytilus edulis Linn., Syst. Nat., Ed. X, 1758, p. 705. = M. Lwrcalis Lam. = M. abbrcviatus Lam.
= M. velustus Lam. = /J/, incurvatus Lam. = M. pcllucidiis Pennant = M. notatus
DEK;yY = M. subsaxatilis Williamson [fide Carpenter. Brit. Assn. Rept. , 1856, p.
219). Carpenter, Brit. Assn. Rept., 1863, p. 643. Cooper, 7th Ann. Rept. Cal. St.
Min., 1888, p. 252. Keep, West Coast Shells, p. 173, 1892. Williamson, Proc.
U. S. Nat. Mus., Vol.XV, 1892, p. 191. = Modiola piilcx H. C. Lea (not of Lam.)
= Mytilus minganensis Mighels, &c. {fide Dall, Wagner Inst. Sci., Vol. Ill, Part 4,
1898, p. 788).
Mytilus pedrmviis Con., Pac. R. R. Rept., Vol. V, 1853, p. 325, PI. V, fig. 40.
ARNOLD — THE PALEONTOLOGY AND STKATIGKAPHY OF SAN PEDRO. 119
Shell of medium size, wedge-shaped, rounded behind, thin; surface smooth, except for
concentric, incremental lines; umbones terminal; dorsal margin slightly depressed in middle; hinge-
teeth minute.
Dimensions. — Long. 55 mm.; lat. 24 mm.; diam. iS mm.
The only difference between the Pleistocene specimens and the living form
is in the coloraiion of the epidermis, that of the former being reddish brown, while
the latter is blue. Specimens identified by Dr. Dall.
Rare in the lower San Pedro series of Deadman Island; and in the upper
San Pedro series of Deadman Island, Crawfish George's, and San Pedro.
Living. — San Pedro (Williamson): Monterey, north; Japan; circiimpolar
(Cooper): Atlantic Ocean south to North Carolina (Dall).
Pleistocene. — Benicia, Solano County (Cooper): San Pedro (Arnold): Atlantic
coast from Labrador to St. John's River, Florida; northern Europe; northwest coast
of Ameriqa (Dall).
Pliocene. — Red Crag, Great Britain (Dall).
Genus Septifer Reduz.
Shell equivalve, very inequilateral; ventral margin subconcave and cut out for the passage
of the byssus; beaks subterminal, curved; hinge without teeth, furnished with a lamellar septum;
ligamental pits linear, marginal, dorsal, anterior, with a white, nearly spongy margin within; muscu-
lar impressions superficial, the anterior small, rounded, the posterior large, subdorsal, uniform.
Septifer heberti Desli. is a characteristic species.
41. Septifer bifurcatus Conrad.
Mylilus bifutcaliis Conrad, Journ. Phil. Acad. Sci., Vol. VII, 1837, p. 241, PI. XVIII, fig. 14.
Reeve, Conch. Icon., PL IX, fig. 41.
Septi/cr bifurcatus RvE., Cakpenter, Brit. Assn. Rept., 1863, p. 643. Gabb, Pal. Cal, Vol. II, 1869,
p. loi. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 264. Keep, West Coast
Shells, p. 171, fig. 144, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892,
p. 191. Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 4, 1898, p. 789.
Shell small, wedge-shaped, equivalve, convex, rather thick; beaks pointed, terminal; surface
sculptured by numerous strong, rounded, terminally bifurcating, radiating ridges, and fine concentric,
incremental sulcations; margin corrugated; a small lamellar deck stretches across the interior of the
shell near the umbo; teeth small.
Dimensions. — Beak to ventral margin 10 mm.; lat. 6 mm.; diam. 4 mm.
This little shell is shaped like a Mylilvs edulis, but is smaller and has
prominent, bifurcating, radiating ridges, delicate incremental sculpture, and an
umbonal deck.
Rare in the lower San Pedro series at Deadman Island.
Living. — Farallon Islands to San Diego (Cooper).
Pleistocene. — Santa Barbara; San Diego (Cooper): San Pedro (Arnold).
120 CALIFORNIA ACADEMY OF SCIENCES.
Genus Modiolus Lanuirck-.
Shell oblong, inflated in front; umbones anterior obtuse; hinge toothless; pedal impressions
three in each valve, the central elongated; epidermis often produced into long beard-like fringes.
Type, Mytilus modiolus Linne.
Section ilodiolus s. s. '
Surface smooth, shell inflated, edentulous, epidermis more or less hirsute.
Type, Mytilus modiolus Linne.
42. Modiolus fornicatus Carpenter.
Modiola fornicaia Cpr., Brit. Assn. Rep., 1863, p. 643; Ann. cS: Mag. Nat. Hist , 3rd Ser., Vul.
XV, 1865, p. 179. Keep, West Coast Shells, p. 173, 1892. Williamson, Proc.
U. S. Nat. Mus., Vol. XV, 1892, p. 191.
Shell of medium size, short, oblong, inflated in front, swollen, equivalve; beaks anterior,
not quite terminal, obtuse, marginal, bent forward; surface sculptured only with concentric incre-
mental lines; margins smooth; no hinge teeth.
Dimensions. — Beaks to ventral margin 54 mm.; lat. 31 mm.; diam. 30 mm.
This species is distinguishable by its short, swollen form.
Rare in the lower San Pedro series of Deadnian Island, and in the upper San
Pedro series of Los Cerritos. Found also in the Pleistocene of Bai'lovv's ranch,
Ventura, and bluff west of bath-liouse, Santa Barbara.
Liviny. — Monterey to Santa Barbara (Carpenter): San Pedro (Williamson).
Pleistocene. — San Pedro (Ai'nold): Ventura; Santa Barbara (Arnold).
43. Modiolus rectus Conrad.
Modiola recta CoN., Journ. Acad. Nat. Sci. Phil., Vol. VII, 1837, p. 243, pi. XIX, fig. i. Carpenter,
Brit. Assn. Rept., 1863, p. 643. Gabb, Pal. Cal. Vol. II, p. loi, 1869. Cooper, 7th
Ann. Rept. Cal. St. Min., 1888, p. 251. Keep, West Coast Shells, p. 171, fig. 145,
1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 192. Dale, Trans.
Wagner Inst. .Sci., Vol. Ill, Part. 4, i8yS, p. 793.
Shell large, rhomboidal, narrow, evenly convex, not sharj^ly ridged, sculptured by numerous
fine, concentric, incremental lines; lower margin a nearly straight line; ligament long, narrow,
straight.
Dimensions. — Long. 150 mm.; alt. 50 mm.; diam. 38 mm.
Specimen identified by Dr. Dall.
Rare in lower San Pedro series of Deadman Island, and the upper San Pedro
series of Deadman Island, San Pedro, and Los Cerritos. Found also in the Pliocene
of Pacific Beach, and the Pleistocene of Pacific Beach and Twenty-sixth Street,
San Diego.
Living. — Santa Cruz to San Diego (Cooper).
ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 121
Pleistocene. — San Pedro (Cooper, Arnold) : San Diego (Arnold).
Pliocene. — Santa Rosa; Twelve Mile House, San Mateo County; Soquel, Santa
Cruz County; San Fernando; San Diego well (Cooper): San Diego (Arnold).
Miocene. — El Toro Ranch, Monterey County; Foxin's, Santa Barbara County
(Cooper).
Genus Lithophaga Bolten.
Shell cylindrical, inflated in front, wedge-shaped behind; epidermis thick and dark; interior
nacreous.
Type, Mijtilus lithophagus Linne.
44. Lithophaga plumula Hanley.
Lithophagus plumnla Hanley, Carpenter, Brit. Assn. Rept. , 1863, p. 644. Keep, West Coast
Shells, p. 171, 1892. Williamson, Proc. U. S. Nat. Mus. , Vol. XV, 1892, p. 192.
Lilhophaga plumula Hanley, Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part. 4, 1898, p. 799.
Shell subcylindric, with nearly terminal beaks; two radial sulci extending backward from
the beaks, incrustation plume-like, arranged in a distinct pattern on the areas between the sulci, and,
when projecting beyond the ends of the valve, apposited symmetrically.
One perfect cast of a shell of this species was found on the inside of a Metis
alia in the upper San Pedro series at Los Cerritos.
Living. — Monterey to San Diego (Carpenter).
Pleistocene. — San Pedi'o (Arnold).
Order ANOMALODESMACEA.
Superfamily ANATINACEA.
Family XIII. PERIPLOMID.E.
Genus Periploma Schumacher.
Shell oval, very inequivalve, inequilateral, slightly nacreous ; left valve deepest; posterior
side very short and contracted; hinge with a narrow, oblique, spoon-shaped process in each valve,
and a small triangular ossicle; an internal rib proceeds from under the hinge to the posterior margin;
muscular impressions unequal, the anterior long and narrow, the posterior small, semilunar; pallial
impression marginal.
Periploma incequivakis Schum. is a characteristic species.
45. Periploma argentaria Conrad.
Periplofna argenlaria CoN., Journ. Phil. Acad. Sci., Vol. VII, 1837, p. 238, PI. XVIII, fig. 8.
Carpenter, Proc. Zool. Soc, 1856, p. 211; Brit. Assn. Rept., 1863, p. 638. Cooper,
7th Ann. Rept. Cal. St. Min., 1888, p. 258. Keep, West Coast Shells, p. 204,
fig- i75> 1892. Dall, mss., 1900.
( 11 ) December 27, 1902.
1'2'J CALIFORNIA ACADEMY OF SCIENCES.
Periplo?na p/aniiiscula Sby. + P. lenlicularis Sby. = P. argcntaria CoN. = P. alta C. B. Ad
= P. excurvaCPR. (fide Stearns, Proc. U. S. Nat. Mus., Vol. XIII, 1890, p. 223).
Dall, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 184.
Shell of medium size, elliptical, inequilateral, inequivalve, fragile; umbones small, anterior
to center; posterior extremity long and evenly rounded, but produced farthest a little above the
middle; anterior portion much shorter than posterior, faintly biangulated; surface sculptured by fine
concentric, incremental lines; hinge a hollow spoon-shaped process, projecting inwards from below
the umbones; this cartilage process is strengthened by an elongated callus slanting anteriorly;
pallial sinus short, cuneiform.
Dimensions. — Long. 46 mm.; alt. 33 mm.; diam. iS mm.; umbo to anterior extremity
13 mm.; to posterior extremity 33 mm.
Specimens identified by Dr. Dall.
Rare in the San Pedro series of San Pedro, Los Cerritos, Crawfish George's,
and Deadman Island. Found also in the Pleistocene at Twenty-sixth Street and
Spanish Bight, San Diego.
Living. — Point Conception south to Mexican coast (Stearns).
Pleistocene. — San Pedro (Arnold): San Diego (Cooper, Arnold.)
Family XIV. THRACIID.E.
Genus Thracia (Leach) Blainville.
Shell oblong, nearly equivalve, slightly compressed, attenuated and gaping posteriorly;
smooth or minutely scabrous; cartilage process thick, not prominent, with a crescentic ossicle;
pallial sinus shallow.
Thracia jJubescens Pult. is a characteristic species.
46. Thracia trapezoides Conrad.
Thracia trapezoides Con., Wilkes Exped., Vol. X, 1849, p. 723, Pi. XVII, fig. 6. Gabb, Pal. Cal. ,
Vol. II, 1869, p. 90. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 267.
Shell of medium size, subtrigonal, compressed, thin ; umbones central, bent slightly posteri-
orly ; anterior margin evenly arcuate from umbones, bending off quite evenly into the arcuate
ventral margin; anterior extremity most produced near base; posterior dorsal margin depressed near
umbo, sloping off slightly concavely to a line which abruptly truncates the posterior extremity ; this
truncating line is slightly arcuate, but is angular at both ends; surface sculptured by faint incre-
mental lines; a prominent fold runs from the umbones to the lower part of the truncated extremity.
Dimensions. — Long. 48 mm.; alt. 38 mm.; diam. 16 mm.
After comparing the San Pedro Pliocene specimens with several Miocene
shells from the Astoria horizon of Blakely, Washington (Conrad's type came from
this same horizon), it is evident that the two forms are identical. The San Pedro
specimens, however, average much larger in size. Dr. Dall labeled these specimens
''Thracia? carta." T. carta is much less depressed behind the beaks, has a much
AENOLD— THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 123
straighter ventral margin, and a more evenly ronnded anterior extremity than
T. trapezoides.
This species is fonnd in only one narrow stratnm of the San Pedro Pliocene.
This stratnm outcrops near the base of Deadraan Island, and also on tlie top of the
ridge at the head of the railroad grade in the southeastern part of San Pedro. It is
the predominating species in this one stratum.
Pliocene. — Eagle Prairie, Humboldt County (Cooper): San Pedro (Arnold).
Miocene. — Oregon (Cooper): Blakely, near Seattle, Washington (Arnold).
Family XV. PANDORIDiE.
Genus Pandora.
Shell inequivalve, tliin, pearly inside; valves close, attenuated behind ; right valve flat, with
a diverging ridge and cartilage furrows ; left valve convex, with two diverging grooves at the hinge;
pallial line slightly sinuated.
Subgenus Kennerlia Carpenter.
Hinge ossicle thin; radiating ribs on the right valve.
Type, Kennerlia bicarinatd Carpenter.
47. Pandora (Kennerlia) bicarinata Carpenter.
Plate XVIII, Fio. 2.
Kennerlia bicarinata CPR., Brit. Assn. Rept., 1863, p. 638; Proc. Zool. Soc, 1S64, p. 603.
Tryon, Syst. Conch., Vol. Ill, 1884, p. 143.
? Pandora bilirata Con., Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 257.
Shell small, planoconvex, oval, thin; umbones minute, about one-third length from anterior
end; anterior and posterior dorsal margins straight, making an angle a little less than 160 degrees
at the umbo; ventral margin arcuate, rounding upward at each end and meeting dorsal margins in
angulated turns; two posterior submargina! ridges run from the umbo to the extremity in the convex
valve; surface sculpture and hinge as in K.filosa.
Dimensions. — Long. 14 mm.; alt. 9 mm.; diam. 3 mm.; umbones to anterior extremity
4 mm.; to posterior extremity 10 mm.
This species is closely related to K.filosa, but is distinguishable by its broader,
shorter shell, rounded rather than beaked po.sterior extremity, and more nearly
central umbones. Probably the same as Pandora bilirata of Conrad.
One left valve from the lower San Pedro series of Deadman Island, which is
6gured, and is now in the possession of Delos Arnold.
Living. — Catalina Island (Carpenter).
Pleistocene. — San Pedro (Aiiiold): Santa Barbara (Cooper).
124 CALIFOENIA ACADEMY OF SCIENCES.
48. Pandora (Kennerlia) filosa Carpenter.
Plate XVIII, Fig. 3.
Kennerlia filosa Cpr., Brit. Assn. Rept., 1863, p. 638; Proc. Zool. Soc. , 1864, p. 602.
Shell small, planoconvex, elongate-oval, thin; umbones minute, about one-fourth length from
anterior extremity; anterior and posterior dorsal margins straight, making an angle of 160 degrees
at the umbo; ventral margin arcuate; posterior extremity long, narrowed and truncated at the end;
anterior rounded up from base but making an angle with dorsal margin ; a single prominent poste-
rior, submarginal ridge runs from umbo to extremity on each valve, being nearer the margin in the
flat valve; surface of both valves sculptured by numerous fine, concentric, incremental lines, and
that of the right valve by fine radiating sulcations; left valve with a thin hinge ossicle; right valve
with two ossicles, the anterior one being short.
Dimensions. — Long. 16 mm.; alt. 7 mm.; diam. 3 mm.; umbo to anterior end 4 mm.; to
posterior end 12 mm.
The right valve of this little shell looks .something like a wing, and resembles
Clidiophora punctata, but is distinguishable by the straight dorsal margin, radiating
sulcations, and narrower form.
Specimens identified by Dr. Dall.
One right and one left valve found in the lower San Pedro series of Deadman
Island. The specimen figured is from the lower Ban Pedro series at Deadman Island,
and is now in the collection of Delos Arnold.
Living. — Puget Sound (Carpenter).
Pleistocene. — San Pedro (Arnold).
Genus Clidiophora Carpenter.
Shell inequivalve, thin, pearly inside; valves close, attenuate behind; right valve rather
tumid, with three hinge teeth, the posterior one elongated; left valve often with two teeth; ossicle
present; pallial line simple.
Clidiophora claviculata Carp, is a characteristic species.
49. Clidiophora punctata Conrad.
Pandora punctata CoN., Journ. Phil. Acad. Sci., Vol. VII, 1837, p. 228, PI. XVII, fig. i.
Clidiophora punctata Con., Cpr., Brit. Assn. Rept., 1863, p. 638. Cpr., Proc. Zoo!. Soc, 1864,
p. 598. Gabb, Pal. Cal., Vol. II, p. 90, 1869. Cooper, 7th Ann. Rept. Cal. St. Min.,
1888, p. 235. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 183.
Shell rather small, suboval, much compressed, thin; umbo posterior to center, marginal,
not elevated; anterior dorsal margin concavely arcuate; anterior extremity rostrated; posterior
extremity evenly rounded; outer surface sculptured with fine, concentric, incremental lines; interior
pearly, punctate; right valve slightly tumid, with three hinge teeth; left valve with two hinge teeth.
Dimensions. — Long. 30 mm.; alt. 19.5 mm.; diam. 5 mm.; umbo to anterior end 21 mm.;
to posterior end 9 mm.
Specimens identified by Dr. Dall.
ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 125
Rare in the lower San Pedro series of Deadmaii Island and upper San Pedro
series of San Pedro. Found also at Spanish Bight, San Diego.
Living. — Straits of Fuca to San Diego (Cooper).
Pleistocene. — San Pedro (Arnold): San Diego (Arnold).
Pliocene. — San Benito County (Coojjer).
Miocene. — Ventura Count}' (Cooper).
Family XVI. LYONSIID.E.
Genus Lyonsia Tiirfon.
Shell nearly equivalve, left valve largest; thin, subnacreous, close, truncated posteriorly;
cartilage plates oblique, covered by an oblong ossicle; pallial sinus obscure, angular.
Lyonsia norvegica is a characteristic species.
50. Lyonsia californica Conrad.
Lyonsia californica Con., Journ. Phil. Acad. Sci., Vol. VII, 1837, p. 248, PI. XIX, fig. 20. Cpr.,
Proc. Zool. Soc, 1856, p. 210; =L. bracteata Gld. =Z-. iiitida Old., {fide Carpen-
ter, Brit. Assn. Rept., 1863, p. 638). Keep, West Coast Shells, p. 202, fig. 174, 1892.
Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 184.
Shell of medium size, elongate-oval, truncated and narrowing slightly posteriorly, convex,
thin; long, slightly depressed posterior to umbo; short, convex anterior; surface sculptured with
fine, concentric, incremental lines; external layer chalky and fugacious, pearly beneath; cartilage-
plates oblique, covered by an oblong ossicle; pallial sinus obscure.
Ditnensions. — Long. 31 mm.; alt. 14 mm.; diam. 11 mm.
This frail shell is generally found with the outer layer gone, leaving the pearly
surface of the lower layer exposed. Outline variable.
Specimens identified by Dr. Dall.
Rather common in the Pliocene of Deadman Island, the lower San Pedro
series of Deadman Island and San Pedro, and the upper San Pedro series of Dead-
man Island, Crawfish George's, and San Pedro.
Living. — Puget Sound to San Diego (Carpenter).
Pleistocene. — San Pedro (Arnold).
Pliocene. — San Pedro (Arnold).
Genus Mytilimeria Conrad.
Shell rounded oval, more or less ventricose, equivalve, fragile, covered by a thin caducous
epidermis; beaks subspiral; hinge without teeth, but formed of small linear excavations under the
beaks to receive the ligament, which contains a small ossicle; muscular impressions small; pallial
impression with an obtuse sinus.
Type, Mytilimeria nvttalli Conrad.
12G CALIFORNIA ACADEMY OF SCIENCES.
51. Mytilimeria nuttalli Conrad.
Plate XVII, Fig. 8.
Mytilimeria tnMa/ii Con., }ourn. Phil. Acad. Sci., Vol. VII, 1837, p. 247. Cpr., Brit. Assn. Rept.,
1863, p. 638. Gabb, Pal. Cal., Vol. II, p. 90, 1869. Tryon, Syst. Conch., Vol. Ill,
1884, p. 147, PI. CVIII.fig;. 68. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 252.
Keep, West Coast Shells, p. 203, 1892.
Shell small, equivalve, suboval, convex, thin; beaks central, subspiral, small; surface sculp-
tured by fine, concentric, incremental lines and numerous delicate radiating sulcations, the whole
having a pearly luster; hinge edentulous, with a slight linear cavity under the beaks; pallial sinus
broad, obtuse.
Divicnsio7is. — Long. 11 mm.; alt. 17 mm,; diam, 10 mm.
Thi.s fragile little shell resembles a very small and broad Mytilns, but is easily
distinguishable by its delicate scnlptnre. Specimens identified by Dr. Dall.
Rare in the Pliocene and lower San Pedro series of Deadman Island, and in
the lower San Pedro series of San Pedro.
The species figured is imperfect. It came from the lower San Pedro series at
Deadman Island, and is now in the collection of Delos Arnold.
Living. — Straits of Fnca to San Diego (Cooper).
Pleiaiocene. — San Pedro (Cooper; Arnold).
Miocene. — Tomales, Marin County (Cooper).
Superfamily POROMYACEA.
Family XVII. VERTICORDIIDiE.
Genus Verticordia S. Wood.
Shell suborbicular, with radiating ribs; beaks subspiral; margins denticulated; interior
brilliantly pearly; hinge with one prominent cardinal tooth in each valve; adductor scars two, faint;
pallial line simple; ligament internal, oblique; epidermis dark brown.
Type, Verticordia cardiiformis Wood.
52. Verticordia novemcostata Adumi^ <£• Reeve.
Plate XVII, Fig. 10.
Verticordia nove^ncostata Ad. & RvE,= V. oriiata D'Orb. (yza'f Cpr., Brit. Assn. Rept., 1863, p. 645.)
Shell small, suborbicular, compressed, thin; beaks subcentral, subspiral, small, sharp,
anterior extremity evenly rounded; posterior dorsal margin evenly arcuate, and joining arcuate
ventral margin in an angular extremity; surface with nine prominent, sharp, arcuate, radiating ridges;
the first and third interspaces wider than the others; margins sharply denticulate; liinge with one
prominent cardinal tooth in each valve; adductor scars two, faint; pallial line simple; ligament
internal, oblique; interior pearly.
Dimensions. — Long. 4 mm.; alt. 3.5 mm.; diam. 2 mm.
ARNOLD — THE PALEONTOLOGY AND STRATIGKAPHY OF SAN PEDRO. 127
This little shell is one of the unique species of this fauna. Specimens identi-
fied by Dr. Dall.
One specimen from lower San Pedro series of Deadman Island, which is
figured, and is now in the collection of Delos Arnold.
Living. — Santa Barbara; Samarang, China; South America (Carpenter):
San Pedro (Raymond).
Pleistocene. — San Pedro (Arnold).
Order TELEODESMACEA.
Superfamily ASTARTACEA.
. Family XVIII. , ASTARTID.E.
Genus Astarte Soiverby.
Shell suborbicular, compressed, thick, smooth, or concentrically furrowed; lunule com-
pressed; ligament external; epidermis dark; hinge-teeth two in each valve, the anterior tooth of the
right valve large and thick ; anterior pedal scar distinct ; pallial line simple.
Astarte semisulcata Leach is a characteristic species.
Subgenus Crassinella Bayle.
Shell obliquely lengthened, subquadrangular.
Astarte ohliqua Dash, is a characteristic species.
53. Astarte (Crassinella) branneri, sp. nov.
Plate XVIII, Fig. 12.
Shell small, subtrigonal, equivalve, inequilateral, convex, thick; umbo small, sharp; ante-
rior dorsal margin straight to anterior extremity, where it meets the arcuate ventral margin in an
angle ; posterior dorsal margin evenly arcuate, sloping down to rounded, posterior extremity ; surface
sculptured with numerous angular, concentric undulations or ridges ; lunule long, narrow, extending
to anterior extremity, and circumscribed by a narrow, angular ridge ; ligament external, not promi-
nent; two prominent cardinal teeth in right valve; one in lelt; no laterals; pallial line entire, running
from the middle of adductor scars ; adductor scars subequal, small.
Dimensions. — Long. 10 mm.; alt. 8.9 mm.; diam. 5 mm.
This species somewhat resembles Astarte compacta Cpr., but has a longer
lunule, finer concentric ridges, and is more bilaterally symmetrical. Specimens
pronounced a new species by Dr. Dall. Named in honor of Dr. John C. Branner,
Professor of Geology, Leland Stanford Junior University.
Rare in the upper San Pedi'o series of San Pedro and Los Cerritos. The
specimen figured is the type, which is from the ujijier San Pedro series at Los
128 CALIFORNIA ACADEMY OF SCIENCES.
Cerritcs, ■ and i.s iiow in tliu United State.s National Museum. Found also in the
Pleistocene of Twenty-sixth Street, Sau Diego.
Pleistocene. — San Pedro; San Diego (Arnold).
Superfamily CARDITACEA.
Family XIX. CAKDITID.E.
Genus Venericardia Lamarck.
Shell siiborbicular, inequilateral, radiately ribbed; hinge widi two oblique cardinal teeth
and no laterals.
Venericardia planicostata Lamarck is a characteristic species.
54. Venericardia barbarensis Stearns.
Venericardia barbarensis Stearns, Proc. U. S. Nat. Mus., Vol. XIII , 1891, p. 214, PI. XVI, figs. 3, 4.
Shell rounded, inequilateral, variable in outline, more or less oblique, moderately convex;
beaks small, slightly elevated and turned forward; surface ornamented with nineteen or twenty radi-
ating ribs, usually somewhat granulose; lunule small, slightly sunken, faintly defined; hinge-line
small, not thick ; hinge composed of, in' left valve, a single strong cardinal sloping posteriorly
and a smaller tooth, often obscure, slanting anteriorly; a third tooth-like process is generally present,
situated under, and apparently a projection of, the edge of the lunule; the right valve has a single
strong cardinal tooth with a slanting, somewhat sinuous groove above and a slight notch and tooth-
like point below the upper part of the lunule; muscle impressions small.
Diiuensiofis. — Long. 19.5 mm.; alt. 17 mm.; diam. 14 mm.
Distinguishable from I', ventricosa by more subrectangular outline, greater
relative length; greater number of ribs, less prominent beak, much narrower and
longer hinge-line, and shorter, slighter posterior cardinal tooth, which is straight.
Common in Pliocene and lower San Pedro series of Deadman Island; rare
in Pliocene at Timm's Point and upper San Pedro series of Crawfish George's and
San Pedro. Found also west of bath-house at Santa Barbara.
Living. — Santa Barbara Islands (276 fathoms) (Stearns).
Pleistocene. — San Pedro (Arnold): Santa Barbara (Arnold).
Pliocene. — San Pedro (Arnold).
55. Venericardia venti-icosa Gim/d.
Cardila ventricosa Gi^u., Proc. Bost. Soc. Nat. Hist., 1850, p. 276; Wilkes Hxpl. E.x[)ed., Vol. XII,
p. 417, PI. XXXVI, fig. 532, 1852, =C. subte7ita Con., =C. monilicosta Gabb, ^C. occi-
dentalis Con., {fide Gabb, Pal. Cal., Vol. II, 1869, p. 100).
Venericardia borealis \-3S . ventricosa Gld., Cpr., Brit. Assn. Rept., iS63,ix 643, Cooper, 7th Ann.
Rept. Cal. St. Min., 1888, p. 269.
Veiiericardia veyitricosa Gld., Stearns, Proc. U. S. Nat. Mus., Vol. XIII, 1891, p. 216, PI. XVI,
figs. 5 and C. W1LLIAM.S0N, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 190.
ARNOLD — THE PALEONTOLOGY AND STKATIGRAPHY OF SAN PEDRO. 129
Shell small, subcircular, ventricose, thick ; umbones slightly anterior to center, much bent
forward, prominent; surface sculptured by about thirteen prominent, rounded, radiating ridges,
which are slightly roughened by regular lines of growth; sulcations narrow; hinge area broad, short;
two prominent teeth in each valve, anterior short; margin closely crenulated.
Dimensions. — Long. 12.5 mm.; alt. 13 mm.; diam. 8 mm.
Distingui.shable by small size, coarse sculpture and heavy hinge. Common in
the Pliocene of Deadman Island and Timin's Point; rare in lower San Pedro series
of Deadman Island. Found also in Pleistocene of Pacific Beach, near San Diego;
and in the Pliocene of Packard's Hill and the Pleistocene near the bath-house,
Santa Barbara.
Living. — Alaska to Cataliua Island (Cooper).
Pleistocene. — Santa Barbara to San Diego (Cooper): San Pedro; Santa Bar-
bara; San Diego (Arnold).
Pliocene. — San Fernando; Santa Barbara to San Diego (Cooper): San Pedro;
Santa Barbara (Arnold).
Miocene. — Oregon; Foxin's, Santa Barbara County; Santa Monica (Cooper):
Blakeley, near Seattle, Washington (Arnold).
Genus Lazaria Conrad.
Shell transverse, oblong, inequilateral; beaks subanterior, radiately ribbed ; hinge with two
cardinal and two lateral diverging teeth in each valve, the posterior teeth being in each case much
elongated, the anterior short and more or less pointed, sublunular.
Lazaria pectunculus Brug. is a characteristic species.
56. Lazaria subquadrata Carpenter.
Lazaria subquadrata Cpr., Brit. Assn. Rept., 1S63, p. 642; Ann. Mag. Nat. Hist., 3d ser.. Vol. XV,
1865, p. 179. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 244. Keep, West Coast
Shells, p. 179, fig. 152, 1892. Williamson, Proc. U. S. Nat. Mus.,Vol. XV, 1892, p. 190.
Shell small, transverse, subrectangular, inequilateral, ventricose, thick; beaks subanterior,
not prominent ; dorsal posterior margin long, straight ; anterior portion abruptly truncated just in
front of beak; surface sculptured with heavy, squamose, rounded, radiating ridges; interior
margin coarsely crenulated; hinge with two lateral diverging teeth in each valve, the posterior teeth
being in each case much elongated, the anterior short and pointed.
Dimensions. — Long. 10 mm.; alt. 6 mm.; diam. 5.6 mm.
Distinguishable by its small size, rectangular outline, and coarse, squamose
ridges which radiate from one corner of the rectangle. Specimens identified
by Dr. Dall.
Rare in the lower San Pedro series of Deadman Island and San Pedro; and
in the upper San Pedro series of Crawfish George's and San Pedro.
Living. — Straits of Fuca to San Diego (Cooper).
Pleistocene. — Santa Barbara (Cooper): San Pedro (Arnold).
( n ) December 29, 1902.
130 CALIFOKNIA ACADEMY OF SCIENCES.
■Superfamily CHAMACEA.
Family XX. CIIAMID.E.
Geuus Chama {Plimj) Linne.
Shell attached usually by the left umbo; valves foliaceous; the ujjper smallest; hinge-tooth
of free valve thick, curved, received between two teeth in the other; adductor impressions large;
oblong, the anterior encroaching on the hinge-tooth.
Chama lazarus Linne is a characteristic species.
57. Chama exogyra Conrad.
Chama exogyra Con., Jour. Phil. Acad. Sci., Vol. VII, 1837, p. 256. Reeve, Conch. Icon., sp. 38,
PI. VII. Carpenter, Proc. Zool. Soc, 1856, p. 217; Brit. Assn. Rept., 1863, p. 641.
Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 233; Bull. Cal. St. Min. Bureau, No. 4,
1894. p. 24. Keep, West Coast Shells, p. 182, 1892. Williamson, U. S. Nat. Mus.,
Vol. XV, 1892, p. 189.
Shell of medium size, oval, irregular; left valve subcompressed, thick, attached when living;
umbo small, submarginal, much twisted, either de.\tral or sinistral, generally the former; surface
foliated with irregular, disconnected, rough, translucent, concentric frills; hinge-tooth thick in free
valve; two teeth in attached valve; adductor impressions large, oblong, the anterior encroaching on
the hinge-tooth.
Dimensions. — Long. 33 mm.; alt. 33 mm.; diam. 16 mm.
Distinguishable from C. fMucida by larger, thicker shell, fewer and less spiny,
though more prominent frills; and by being attached generally by the left valve.
Specimens identified by Dr. Dall.
Rare in upper San Pedro series of San Pedro and Los Cerritos.
Living. — Bodega Bay to San Diego; Mexico (Cooper).
Pkidocene. — Santa Barbara to San Pedro (Cooper): San Pedro (Arnold): San
Nicolas Island (Bowers).
58. Chama pellucida Soiverbi/.
Chama spinosa Brod. vi,x. pellucida Sv.y., Proc. Zool. Soc, 1834, p. 150.
Chama pellucida Sby., Cpr., Brit. Assn. Rept., 1S63, p. 641. Keep, West Coast Shells, p. 182,
fig. 155, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 189. Cooper,
Bull. Cal. St. Min. Bureau, No. 4, 1894, p. 24.
Shell of medium size; right valve (attached), exceedingly ventricose, rather thin; left valve
nearly flat, thicker; surface of attached valve sculptured with numerous prominent, spiny frills; surface
of upper valve with more numerous, small frills, which are sometimes spiny near the margin of the
valve; hinge-teeth and muscle-impressions as in C. exogyra.
Dimensions. — Long. 20 mm.; alt. 25 mm.; diam. 15 mm.
Distinguishable from C. exogyra by smaller size, more prominent frills on
upper valve, and by the fact that in C. pellucida the right valve is generally attached,
■Hid is exceedingly ventricose, while in 0. exogyra the left valve is the larger, and is
attached. Specimens identified by Dr. Dall.
ARNOLD — THE PALEONTOLOGY AND STEATIGRAPHY OF SAN PEDRO. 131
Rather common in the Pliocene; rarer in the lower San Pedro series of Dead-
man island; and only found occasionally in the upper San Pedro series of San Pedro,
Deadman Island, Los Cerritos, and Crawfish George's.
Living. — San Francisco to San Diego (Carpenter).
Pleistocene. — San Pedro (Arnold).
Pliocene. — Ventura County (Bowers).
Superfamily LUCINACEA.
Family XXI. LUCINIDJ^I
Genus Lucina Brugih-e.
Shell orbicular, white; umbones depressed; lunule distinct; margins smooth or minutely
crenulated ; ligament oblique, semi-internal; hinge-teeth two in each valve; laterals, two in right
valve, four in left ; muscular impressions rugose ; anterior elongated within the pallial line, posterior
oblong; umbonal area with an oblique furrow.
Lucina jamaicensis Linne is a characteristic species.
59. Lucina acutilineata Conrad.
Lucina acutilineata Con., Wilkes Expl. Exped., Vol. X, p. 725, PI. XVIII, fig. 2, 1849.
Cyclas acutilineata Con., Jour. Conch., 1865, p. 153.
Lucina borealis (not of Linn.BUS, Syst. Nat., Edition XII, p. 1413); of Cpr., Brit. Assn. Rept., 1863,
p. 643; ^= Pectunculus patulus Con., Jour. Conch., 1865, p. 153; not Wilkes Expl.
Exped., p. 726 PI. XVIII, fig. 9; =^Lucina tetrica CoN. {fide Gabb, Pal. Cal., Vol. II,
p. 100, 1869). Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 246.
Shell large, orbicular, only slightly convex, rather thin; umbones depressed, central; surface
ornamented by numerous equal, equidistant, sharp, raised, concentric lines; interspaces show lines of
growth; lunule small, but deeply impressed and distinct; two sharp cardinal teeth in each valve;
lateral teeth nearly obsolete; anterior muscle-impression much elongated.
Dimensiojis. — Long. 57 mm.; alt. 53 mm.; diam. 28 mm.
This species is easily distinguishable by its large size and sharp, concentric,
raised lines. This beautiful shell is always found in a fine .state of preservation in
the Deadman Island formations, in many cases occurring in pairs. The .shell is
translucent, and in only a few instances have imperfect specimens been found. The
convexity of the shell is slightly variable, being more in the younger shells, the older
ones being inclined to become flatter. The Pliocene specimens are smaller, more
convex, and have the concentric lines much closer set than do the Pleistocene forms.
Sjiecimens identified by Dr. Dall.
Common in Pliocene and lower San Pedro series of Deadman Island and San
Pedro; rare in the upper San Pedro series of Deadman Island, Crawfish George's, and
San Pedro. Only one or two specimens have been found in each of the upper San
Pedro localities; thus practically restricting the northern species to the Pliocene and
132 CALIFORNIA ACADEMY OF SCIENCES.
lower San Pedro series. Found also in the Pleistocene west of bath-house, Santa
Barbara; and in the Pleistocene of Pacific Beach, San Diego.
Living. — Catalina Island (Cooper) : Santa Barbara channel (Carpenter) : Puget
Sound (Arnold).
Pleistocene. — Santa Barbara to San Diego (Cooj)er) : San Pedro; Santa Bar-
bara; San Diego (Arnold).
Pliocene. — Santa Rosa; Santa Cruz; Sargent's, Santa Clara County; Santa
Barbara; San Fernando; San Diego well (Cooper): Stanford University (Arnold).
Miocene. — Oregon; Martinez; Griswold's, San Benito County; Orestima Can-
yon, Stanislaus County; Foxin's, Santa Barbara County (Cooper): Point Blakely,
near Seattle, Washington (Arnold).
60. Lucina calif ornica Conrad.
Liicina californica CoN.,Jour. Phil. Acad. Sci., Vol. VII, 1837, p. 255, PI. XX, fig. I. CPR., Brit.
Assn. Rept., 1863, p. 642. Gabb, Pal. Cal., Vol. II, 1869, p. 100. Cooper, 7th Ann.
Rept. Cal. St. Min., 1888, p. 247. Keep, West Coast Shells, p. 178, fig. 151, 1892.
Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 190.
Shell of medium size, orbicular, only slightly conve.x, rather thick; umbones depressed,
central; surface ornamented with numerous fine, close- set, sharp, concentric lines and very faint, fine,
radiating strife; lunule small but distinct, deep-set, wholly in right valve; ligament prominent; two
cardinal teeth in each valve ; two prominent anterior, lateral teeth in left valve, one in right valve,
other laterals small ; muscle-impressions as in L. acutilineaia.
Dimensions. — Long. 31 mm.; alt. 29 mm.; diam. 16 mm.
Distinguishable from L. acutilineaia by smaller size, close-set, concentric lines,
and having the lunule wholly within the right valve.
Found in the Pliocene of Deadraan Island; in the lower San Pedro series of
Deadraan Island and San Pedro; and rarely in the upper San Pedro series at Craw-
fish George's, San Pedro, Los Cerritos, Deadman Island, and Long Beach. Found
also in the Pleistocene at the bath-house, Santa Barbara, and in the Pleistocene of
Pacific Beach, San Diego.
Living. — Santa Cruz to San Diego (Cooper).
Pleistocene. — Santa Barbara; San Pedro (Cooper): San Pedro; Santa Bar-
bara; San Diego (Arnold).
61. Lucina nuttalli Conrad.
Lucina nnttalli Con., Jour. Phil. Acad. Sci., Vol. VII, 1837, p. 255, fig. 2, PI. XX. Cpr., Brit.
Assn. Rept., 1863, p. 642. Gabb, Pal. Cal., Vol. II, p. 100, 1869. Cooper, 7th Ann.
Rept. Cal. St. Min., 1888, p. 247. Keep, West Coast Shells, p. 179, 1892. Williamson,
Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 190.
Shell small, orbicular, only slightly convex, thin; umbones depressed, small, central; surface
ornamented by numerous sharp, regular, concentric lines and prominent radiating grooves, which are
most prominent near the ends, the whole giving a rather cancellated appearance to the surface; lunule
small, nearly all in left valve; hinge and interior as in Z,. californica.
Dimensions. — Long. 20 mm.; alt. 20 mm.; diam. 10 mm.
AENOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 133
Distinguishable by small size, cancellated surface, and luniile in left valve.
Specimens identified by Dr. Dall.
Common in the lower San Pedro series of Deadman Island and San Pedro;
and in the upper San Pedro series of San Pedro, Los Cerritos, Crawfish George's,
Deadman Island, and Long Beach. Found also in the Pliocene of Pacific Beach, and
the Pleistocene of Twenty-sixth Street and Pacific Beach, San Diego.
Living. — Monterey to San Diego (Cooper).
Pleistocene. — Santa Barbara; San Pedro (Cooj)er) : San Pedro; San Diego
(Arnold).
Pliocene. — San Diego (Arnold).
62. Lucina tenuisculpta Carpenter.
Lucina tenuisculpta Cpr., Brit. Assn. Rept., 1S63, p. 642. Cooper, 7th Ann. Rept. Cal. St. Min.,
18S8, p. 247.
Shell small, orbicular, deeply convex, thin; umbones prominent, central ; surface sculptured
by numerous fine, concentric lines and radiating striae; lunule prominent, the greater part being in
the right valve; cardinal teeth small, laterals prominent ; anterior muscle-impressions not as elongated
as in L. acutilineata and others.
DimensioJis. — Long. 9 mm.; alt. 8.8 mm.; diam. 6.4 mm.
Distinguishable by small size, sculptured surface, and great convexity. This
sjiecies resembles Diplodonta orhella very closely in shape and size, but may be
distinguished by the lack of jirominent cardinal teeth, by its lateral teeth, and by the
radiating striae. Specimens identified by Dr. Dall.
Rare in the upper San Pedro series of San Pedro. Found also in the Pleis-
tocene of Spani.sh Bight, San Diego.
Living. — Straits of Fuca to Catalina Island; Mazatlan (Cooper).
Pleistocene. — San Pedro; San Diego (Arnold).
Pliocene. — San Diego well (Dall).
Family XXIL DIPLODONTID^.
Genus Diplodonta Brown.
Section Diplodonta s. s.
Shell rotund, equilateral, externally concentrically striated or smooth, with inconspicuous
epidermis; two cardinal teeth in each valve, of which the right posterior and the left anterior are
distally sulcate or bifid; no lateral teeth; the hinge-plate when developed is usually excavated distally-
there is no circumscribed lunuIe or escutcheon; the adductor scars are subequal, continuous with the
pallial line, and close to the hinge-plate; the margin is entire, the pallial line simple, and pallial area
often radiately striate.
Type, Diplodonta hqnnus Brocchi.
134 CALIFORNIA ACADEMY OF SCIENCES.
63. Diplodonta orbella Gould.
Plate XVIII, Figs. 8 and 8rt.
Lticina orbella Gld. , Proc. Bost. Soc. Nat. Hist., Vol. IV, 1851, p. 90; Bost. Jour. Nat. Hist., Vol.
VI, 1853, p. 395, PI. XV, fig. 3; Cal. & Mex. Shells, p. 22, PI. XV, fig. 3.
Diplodonta orbella Gld., Gould & Carpenter, Proc. Zool. Soc, 1856, pp. 202, 218. '=( Mysia)
Sphairella tumida CoN. {Jide Cpr., Brit. Assn. Rept. , 1863, p. 643). Cooper, 7th Ann.
Rept. Cal. St. Min., 1888, p. 238. Keep, West Coast Shells, p. 179, 1892. Williamson,
Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 190. Dall, Trans. Wagner Inst. Sci., Vol.
Ill, Part 5, 1900, p. 1189.
Shell small, subglobose, thin; beaks nearly median, not prominent; surface sculptured with
fine incremental lines, which at some parts are more conspicuous than at others and render the surface
somewhat irregular; no distinct lunule; ligament prominent; two cardinal teeth in right valve, of
which the anterior is smallest, and the posterior bifid; and two in the left valve, of which the anterior
is bifid, and the posterior very oblique; no lateral teeth; muscle-impressions large, faint.
Dimensions. — Long. 11. 9 mm.; alt. 11. 9 mm.; diam. 9 mm.
Kesembles Lucina tenuiscidpia, but may be distinguished by lack of radiating
stria?, and by the prominent cardinal teeth and hick of lateral teeth. Sjiecimens
identified by Dr. Dall.
Rare in the lower San Pedro series at Deadman Island; and the upper San
Pedro series of San Pedro and Crawfish George's. Found also in the Pleistocene of
Twenty-sixth Street, San Diego. The specimen figured is from the lower San Pedro
series of Deadman Island, and is now in the collection of Delos Arnold.
Living. — Straits of Fuca to San Diego (Cooper).
Pleistocene. — San Pedro to San Diego (Cooper): San Pedro; San Diego
(Arnold).
Pliocene. — San Diego well (Dall).
64. Diplodonta serricata Reeve.
Plate XVIII, Fios. 5 and 5n.
Diplodonta serricata Rye., Cpr., Brit. Assn. Rept., 1S56, p. 248.
Shell small, orbicular, only slightly convex, thin; umbones central, not prominent ; surface
sculptured with numerous fine, incremental lines, which are regular in prominence; lunule not distinct;
hinge prominent; teeth and interior as in D. orbella.
Dimensions. — Long. 13.8 mm.; alt. 14 mm.; diam. 7 mm.
Distinguishable from D. orhclla by its much less convexity and more regular
concentric lines. Specimens identified by Dr. Dall.
Not uncommon in the upi^er San Pedro series of San Pedro. This species is
very common in the Pleistocene deposits at Twenty-sixth Street, San Diego. The
specimen figured is from this horizon, and is now in the collection of Delos Arnold.
Living. — Mazatlan (Carpenter).
Pleistocene. — San Pedro; San Diego (Arnohl).
ARNOLD — THE PALEONTOLOGY AND STKATIGRAPHY OF SAN PEDKO. 135
Family XXIII. CRYPTODONTID^E.
Genus Thyasira Leach.
Shell globular, posterior side furrowed or angulated; umbones much recurved; lunule short or
indistinct; ligament usually and to a certain extent external, placed in a groove on the hinge-line,
and outside the hinge-plate; teeth altogether wanting.
llujaslra Jiexuosus Mont, is ;i characteristic species.
65. Thyasira bisecta Conrad.
Platf, XV. Fig. 5.
Venus bisecta Con., Wilkes Expl. Exped., Vol. X, App. i, p. 724, PI. XVII, figs. 10, loa, 1849.
Thyatira? bisecta Con., Meek, Smithsonian Inst., Check-List Mioc. Fossils, 1864.
Cyprina bisecta Co*i., Jour. Conch., 1S65, p. 153.
Conchocele bisecta CoN. Gabb., Pal. Cal., Vol. II, p. 99, 1869.
Coyichoccle disjuncta Gabb, Pal. Cal., Vol. II, pp. 28, 29, PI. VII, fig. 48, 1869. Cooper, 7th Ann.
Rept. Cal. St. Min., 1888, p. 236.
Cryptodon bisectus Con., Dall, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 189; Vol. XVII, 1894, P-
713, PI. XXVI, figs. 2-5.
Shell large, subquadrate, convex, of medium thickness, equivalve, inequilateral ; beaks
terminal, anterior; anterior end abruptly and angularly truncated; posterior dorsal margin arcuate,
sloping down toward posterior extremity; surface marked only by lines of growth except near the
posterior part, where the peculiar truncation takes place, the surface suddenly descending at right
angles to the curve of the shell, for a short distance, and then resuming its former direction ; ligament
long and elliptical; large lunular area in front of the beaks.
Dimensions. — Long. 72 mm.; alt. 62 mm.; diam. 41 mm.
Specimens identified by Dr. Dall.
Gabb describes this shell as occurring in the Miocene of Deadmau Island, while
Cooper gives its occurrence as in the " Quaternary " of the same place. It is found
most abundantly in a hard stratum near the base of the Deadraan Island Pliocene
deposits; a few shells, however, have been found in Pliocene strata above this layer;
found also at Timm's Point in the Pliocene. Tlie specimen figured is from the
Pliocene of Deadman Island, and is now in the collection of Delos Arnold.
Living. — Paget Sound, sixty-nine fathoms (Dall).
Pliocene. — San Pedro (Arnold).
Miocene. — Astoria, Oregon (Conrad): Blakely, near Seattle, Washington
(Arnold).
66. Thyasira gouldi Philippi.
Cryptodon flexuosHs (not of Montagu) of Carpenter,- Brit. Assn. Rept., 1S63, p. 643. Cooper, 7th
Ann. Rept. Cal. St. Min., 1888, p. 237.
Shell small, globular, posterior side angulated or furrowed ; umbones much recurved ; sur-
face sculptured with fine incremental lines ; lunule indistinct, depressed in front of beaks ; ligament
external, placed in a groove on the hinge-line and outside the hinge-plate ; teeth wanting.
Dimensions. — Long. 9.5 mm.; alt. 11 mm.; diam. 8 mm.
136 CALIFORNIA ACADEMY OP SCIENCES.
This species is distinguishable from T. biaecta by its much smaller size, more
central umbones and less prominent lunule. Dr. Dall says that 2\ gouldi has been
mistaken for Cryptodon flexuosus by West Coast collectors.
Rather common in the Pleistocene of Dead Man Island and Timm's Point.
Not found above the horizon in the San Pedro deposits, so far as known.
Living. — Catalina Island (Cooper): Catalina Island, ten fathoms (Arnold).
Pleistocene. — Santa Barbara (Cooper).
Pliocene. — Santa Barbara; San Diego well (Cooper): San Pedro (Arnold).
Superfamily LEPTONACEA.
Family XXIV. LEPTONID^.
Genus Bornia I'hiUjrpl.
Shell ovate or subtrigonal, subequilateral, with a more or less flattened disk; the peri-
ostracum usually brilliant; the surface smooth or divaricately more or less plicate; pallial line not
sinuated, and the pallial area piquantly punctate or radially striate; hinge with one moderately long
posterior, and two shorter anterior, lamina- in the left valve; in the right, one anterior and one
longer, sometimes remote, posterior lamina; one or both of the anterior laminae in either valve may
have the aspect of cardinals; hinge-plate usually excavated.
Ty2:)e, Bornia corhuloides (Phil.).
67. Bornia retifera Dull.
Plate XVII, Fig. 12.
Bornia retifera Dall, Proc. U. S. Nat. Mus., Vol. XXI, 1899, p. 889, PI. LXXXVII, fig. 2.
Shell thin, white, moderately conve.x, rounded, trigonal, nearly equilateral; beaks distinct,
not high; surface polished, with faint incremental lines and minute, close punctations whose inter-
spaces give the effect of a fine netting ; hinge narrow, delicate; one tooth opposite beak, then a
depression posterior to this, and then a second tooth completely filling the anterior end of the
posterior ligamental groove; adductor scars rounded and high up.
Dimensio7is — Long. 7 mm.; alt. 5.5 mm.; diam. 3 mm.
Looks like a Kellla laperou»ii, but is distinguishable by the microscopic
sculpture and hinge. Specimens identified by Dr. Dall.
One right valve from the lower San Pedro series of Deadman Island, which is
figured herewith, and is now in the collection of Delos Arnold.
Living. — Station 2,900, thirteen fathoms, off Santa Barbara (Dall).
Pleistocene. — San Pedro (Arnold).
Genus Kellia Turton.
Section Kellia Turtou a. s.
Shell rounded and inflated, concentrically striated or smooth ; with an obsolete external
ligament and a large internal resilium without a lithodesma ; two anterior and two posterior teeth in
ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 137
each valve, of which the anterior ones are shorter and may be concrescent or free and pustular ;
interior of valves commonly shows radial striation; and valves frequently distorted.
Type, Kellia suborbicularis (Montagu).
68. Kellia laperousii Deshayes.
Pl.ate XVIII, Figs. 7 and la.
Kellia laperousii Desh., Carpenter, Brit. Assn. Rept., 1863, p. 6+3. Keep, West Coast Shells, p.
178, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 191. Dall, Trans.
Wagner Inst. Sci., Vol. Ill, Part 5, 1900, p. 1155.
Shell of medium size, suborbicular, convex, thin; umbones slightly anterior, not prominent;
surface sculptured by fine incremental lines which are slightly variable as to prominence; no lunule;
each valve with one very prominent cardinal tooth ; right valve with two posterior laterals, left with
one; hinge-area lacking between cardinal and lateral teeth; muscle-impressions not distinct.
Dimensions. — Long. 23 mm.; alt. 19 mm.; diam. ii mm.
Di3tingai.shable from K. suborbicularis by its larger size and less convexity.
These two species may be recognized by their thin, suborbicular shells, and the lack
of a hinge-area in the region of the uiubones, the vacancy at first giving the impres-
sion that the hinge-area has been broken. Specimens identified by Dr. Dall.
Rare in lower !San Pedro series of San Pedro and Deadman Island. One
perfect valve from the Pliocene at Deadman Island. Found also in the Pleistocene
of Spanish Bight, San Diego. The specimen figured is from the lower San Pedro
series at Deadman Island, and is now in the collection of Delos Arnold.
Living. — Puget Sound to Monterey (Carpenter).
Pleistocene. — San Pedro (Arnold): San Diego (Arnold).
Pliocene. — San Pedro (Arnold).
69. Kellia suborbicularis Montatju.
Plate XVIII, Figs. I and la.
Kellia suborbicularis Mont., Testacea Britannica, pp. 39, 564, PI. XXVI, fig. 6, 1804. Carpenter,
Brit. Assn. Rept., 1863, p. 643. Tryon, Syst. Conch., Vol. Ill, p. 220, PL CXX,
fig. 2, 1884. Keep, West Coast Shells, p. 177, 1892. William.son, Proc U. S. Nat.
Mus., Vol. XV, ,1892, p. 191. Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 5,
1900, p. II 55.
Shell small, suborbicular, deeply convex, thin; beaks small, slightly anterior; surface orna-
mented with fine lines of growth which become somewhat irregularly constricted near margin,
roughening the surface; no lunule; margins smooth; hinge and teeth as in K laperousii.
Dimensions. — Long. 8.4 mm.; alt. 7.4 mm.; diam. 5.8 mm.
Distinguishable from K. laperousii by smaller size and greater convexity.
Specimens identified by Dr. Dall.
Rare in lower San Pedro series of San Pedro and Deadman Island. The
( 18 ) December 31, 1902.
138 CALIFOKNIA ACADEMY OF SCIENCES.
specimen fii^urecl is from tlie lower San Petlro series at Deachnaii Island, and is now
in the collection of Delos Arnold.
Living. — Puget Sound to Lower California; England (Carpenter).
Pleistocene. — San Pedro (Arnold).
Funiily XXV. KELLIELLID.E.
Genus Aligeua //. G. Lea.
Shtll rounded, triangular, inflated; single small anterior tooth under the beaks, separated
by a gap from the surface ot attachment, under the posterior dorsal margin, of an elongate internal
resilium carrying a lithodisma.
Type, Aligeua striata (Lea).
70. Aligena cerritensis, sp. no v.
Plate XIII, Fig. 3.
Shell small, rounded, triangular, inflated, thin; inequilateral, the umbo being nearly terminal
posteriorly; anterior dorsal margin nearly straight; anterior extremity quite sharply rounded and
produced furthest below middle; posterior extremity sloping off abruptly from umbo and rounded
near base; ventral margin arcuate; surface with faint concentric sculpture; umbones small, pointed,
anteriorly twisted, with a minute tooth below them on the cardinal margin; pallial line entire; muscle-
scars subequal.
Dimensions. — Long. S.5 mm.; alt. 8 mm.; diam. 5 mm.
This species resembles Acila castrensis in outline. Specimens identified by
Dr. Dall, who pronounced it a new species.
Two specimens from the upper San Pedro series of Los Cerritos, one of which
is the type, which is figured, and is now in the United States National Museum.
Pleistocene. — San Pedro (Arnold).
Superfamily CARDLVCEA.
Funiily XXVI. GARDIID/E. ■
Genus Cardium (Linne) Lamarck.
Shell variably sculptured, usually with predominantly radial ornamentation, usually closed
or gaping but slightly, with no lunula or escutcheon ; pallial line rather distant from the margin of
tile valves.
Subgenus Trachycardium March.
Shell rotund, closed, with the ribs imbricate or granulose; the channels also sometimes
granulose ; left cardinals anterior when interlocked.
Type, Cardium iAnrarilia (Liiinc).
AENOLD— THE PALEONTOLOGY AND STRATIGEAPHY OF SAN PEDRO. 139
71. Cardium (Trachycardium) quadrigenarium Conrad.
Cardt7im qtiadrigenarUim CoN., Jour. Phil. Acad. Sci., Vol. VII, 1837, p. 230, PI. XVII, fig. 5;
= Inteolabriim Gld. (tJo'i? Carpenter, Brit. Assn. Rept., 1863, p. 642). Cooper, 7th
Ann. Rept. Cal. St. Min., 1888, page 232. Keep, West Coast Shells, p. 192, 1892.
Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 190. Dall, Trans. Wagner
Inst. Sci., Vol. Ill, Part. 5, 1900, p. 1091.
Shell large, oval, ventricose, thick; umbones central, prominent, turned only slightly an-
teriorly; surface sculptured with about forty prominent, subangular, smooth, radiating ridges, which
are roughened by prominent pointed tubercles on their posterior angle; those ridges near the pos-
terior margin are less prominent, but are nodose for nearly their whole length; teeth and interior as
in C. cordis: margin sharply serrated.
Dimensiotis. — Long. 105 mm.; alt, 105 mm.; diam. 86 mm.
Distinguishable by laro;e .size and tuberculated ridges. Specimens identified
by Dr. Dall.
Found in the upper San Pedro series of San Pedro, Los Cerritos and the
Long Beach bluff. Found also in the Pleistocene of Twenty-sixth Street and Pacific
Beach, San Diego.
Living. — Monterey to San Diego (Cooper).
Pleistocene. — San Pedro (Arnold): San Diego (Cooper; Arnold).
Pliocene. — Calleguas Ranch, Ventura County (Cooper).
Subgenus Ringicardium Fischer.
Shell rotund, gaping, with flat ribs and channels, the posterior area with granulose channels;
posterior margin sharply spinose, the spines crossing each other over the gap; left cardinals when
interlocked posterior to the right ones.
Type, Cnrdium ringens (Gmel.).
72. Cardium (Ringicardium) procerum Sowerhy.
Plate XV, Fig. 6.
Cardmm p7-occrui>i Sby., Carpenter, Brit. Assn. Rept., 1863, p. 620. Dall, Trans. Wagner Inst.
Sci., Vol. Ill, Part 5, 1900, p. 1091.
Cardmm panamense , not of Sby., of Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 232.
Shell of medium size, suboval, of medium thickness, ventricose, with a rather angular
appearance at about one-fourth the length from the anterior margin; surface sculptured by about 22
subangular, smooth radiating ridges, with narrow, canel-like grooves between; each valve with
three very prominent sharp teeth; margin sharply serrate.
Dimensions — Long, i mm.; alt. 23 mm.; diam. 19 mm.
Distinguishable by angular appearance near anterior side, and by the com-
paratively small number of smooth radiating ridges. Specimens identified by Dr. Dall.
Rather common in the upper San Pedro series of San Pedro, Long Beach and
Los Cerritos; one specimen from the lower San Pedro series of Deadman Island. The
specimen figured is from the upper San Pedro series at San Pedro, and is now in the
140 CALIFORNIA ACADEMY OF SCIENCES.
collection of Delos Arnold. Found abundantly in the Pleistocene of Twenty-sixth
Street and Spanish Bight, San Diego.
Living. — Gulf of California to Panama (Dall).
Pleistocene. — San Pedro (Cooper; Arnold): San Diego (Cooper; Dall; Arnold).
Subgenus Cerastoderma Movch..
Shell rotund or obovate, closed; with strong ribs obsoletely granulosa or intricate or smooth;
no posterior or anterior area; channels single; hinge normal.
Type, Cardium edule (Linne).
73. Cardium (Cerastoderma) corbis Mariyn.
Pectunculis corbis Mart., Univ. Conch., PI. XXVIII, fig. 2, p. 1784.
Cardium corbis Mart., Carpenter, Brit. Assn. Rept., 1863, p. 642, ^=C. californicum Con. =C.
7milalli Co-a. {fide Gabb, Pal. Cal., Vol. II. p. 98, 1869). Cooper, 7th Ann. Rept. Cal.
St. Min., 1888, p. 232. Keep, West Coast Shells, p. 180, fig. 153, 1892. Dall, Trans.
Wagner Inst. Sci., Vol. Ill, Part 5, 1900, p. 1093.
Shell large, subtrigonal, ventricose, thick; umbones prominent, anterior to center; surface
ornamented with about thirty-seven prominent, regular, squarish, close-set, radiating ridges, which are
made more or less rugose by incremental ridges on their surface; near the posterior margin these
ridges become more rounded and less prominent; between the ridges are equal, deep, canal-like grooves;
margin crenulated; ligament short, external, prominent; each valve with one prominent cardinal
tooth, and two laterals, one anterior and the other posterior; muscle impressions prominent, subequal.
Dimensions.- — Long. 71 mm.; alt. 71 mm.; diam. 57 mm.
Distinguishable by the regular, only slightly rugose ridges. Specimens
identified by Dr. Dall.
Found in the lower San Pedro series of Deadman Island and San Pedro; and
in the upper San Pedro series of Deadman Island, San Pedro, Los Cerritos and Crawfish
George's. Found also in the Pleistocene of the bath-house, Santa Barbara.
Living. — Kodiak to Santa Barbara; Kamtschatka (Cooper).
Pleistocene. — San Francisco; Monterey; San Pedro (Cooper): San Pedro;
Santa Barbara (Arnold).
Subgenus Laevicardium Swainson.
Shell thin, oval, closed; middle of the valves smooth or feebly radially sculptured; ends
with a smooth area; hinge normal, but with the anterior laterals springing from the umbonal cavity;
periostracum smooth.
Type, Cnrdiuin norvegiciim (Spengler).
ARNOLD— THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 141
74. Cardium (Laevicardium) elatum Sowcrby.
Plate XX.
Cardium e/atum S^\'., Conch III, Vol. I, 1838. Reeve, Conch. Icon., PI. VIII, fig- 41. Valen-
ciennes, Voy. Venus, PI. XVII, fig. r, 1846.
Liocardium elatum Sby., Carpenter, Brit. Assn. Rept. , 1863, p. 642. Cooper, 7th Ann. Rept. Cal.
St. Min., 1888, p. 246. Keep, West Coast Shells, p. 181, 1892. Williamson, Proc.
U. S. Nat. Mus., Vol. XV, 1892, p. 190.
Lcsvicardium elatum Sby., Gabb, Pal. Cal., Vol. II, p. 99, 1869. Dall, Trans. Wagner Inst.
Sci., Vol. Ill, Part 5, 1900, p. 11 11.
Shell large, oval, oblique, elongated, equivalve, somewhat inequilateral ; surface sculptured
by numerous faint, squarish, radiating ribs, and fine, wavy incremental lines; inner surface of margin
corrugated ; hinge strong, with one prominent cardinal and one prominent anterior lateral tooth in
each valve ; muscle-impressions distinct.
Dimeyisions. — Long. 144 mm.; alt. 167 mm.; diam. 136 mm.
This is the largest of the Gardiidm, and is easily recognizable by its immense
size and nearly smooth surface. A tine pair of this species, described above, and
figured, was found in the upper San Pedro series at the north end of the San Pedro
bluflf. Another specimen was obtained by Dr. A. A. Wright and Mrs. Oldroyd in
tlie upper San Pedro deposits of Los Cerritos. This species is one of the typical
southern forms found in the upper San Pedro series.
Living. — San Pedro to Mazatlan (Cooper).
Pleistocene. — San Pedro (Cooper; Arnold): San Diego (Gabb; Dall).
75. Cardium (Laevicardium) substriatum Conrad.
Cardium substriatum Con., Jour. Phil. Acad. Sci , Vol. VII, 1837, p. 228, PI. XVII, fig. 2.
Liocardium substriatum Coti , ^= cruentatum Gould, {Jide Carpenter, Brit. Assn. Rept., 1863,
p. 642.) Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 246. Keep, West Coast
Shells, p. 181, fig. 154, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892,
p. 190.
Lcsvicardium substriatum Con., Gabb, Pal. Cal., Vol. II, p. 99, 1869. Dall, Trans. Wagner Inst.
Sci., Vol. Ill, Part 5, 1900, page mi.
Shell small, obliquely ovate, ventricose, thin ; surface smooth, except for minute incre-
mental lines and nearly obsolete radiating striae ; one small sharp cardinal tooth in each valve ; two
narrow elongated lateral teeth in each valve, the posterior one in the left valve not prominent ;
interior of margin finely crenulated.
Dimensions. — Long. 17 mm.; alt. 18 mm.; diam. 13 mm.
Distinguishable by its small size and smooth surface. Specimens identified
by Dr. Dall.
Rare in the lower San Pedro series of Deadman Island and San Pedro, and
in the upper San Pedro series of Deadman Island, San Pedro, Crawfish George's,
and Los Cerritos. Found also in the Pleistocene at Twent3r-sixth Street, San Diego.
Living. — Monterey to South America (Cooper).
Pleistocene. — Santa Barbara; San Pedro; San Diego (Cooper): San Pedro
(Arnold): San Diego (Arnold).
142 CALIFORNIA ACADEMY OF SCIENCES.
Genus Protocardia Beyrich.
Shell globose, with a posterior area sharply distinguished by sculpture from the rest of the
surface; closed; hinge normal; no lunule or escutcheon.
Type, Cardium hillaniim (Sowerby).
76. Protocardia centifilosa Carpenter.
Cardiiim var. centifilosmn Cpr., Brit. Assn. Rept. 1863, p. 642.
Cardium ccntifilosian Cpr., Gabb, Pal. Cal., Vol. II, p. 99, 1869. Cooper, yth Ann. Rept. Cat. St.
Min., 1888, p. 232. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 189.
Protocardia centifilosa CpR., Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 5, 1900, p. 11 13.
Shell small, suboval, ventricose, thin; umbones central, prominent, only very slightly bent;
surface sculptured by numerous fine, close-set, rounded, radiating ridges, which are made slightly
rugose by numerous fine, incremental lines on their surface; thin, sharp teeth in each valve; pallial
sinus shallow, wide; margin beautifully and sharply serrate.
Ditnensiotis . — Long. 23 mm.; alt. 22.5 mm.; diam. 15 mm..
Distinguishable by tlie nearly circular outline and numerous fine, radiating
ridges. Specimens identified by Dr. Dall.
Not uncommon in the Pliocene of Deadman Island and Timm's Point; rare in
the lower San Pedro .series of Deadman Island. Found also in the Pleistocene at
bath-house and the Pliocene of Packard's Hill, Santa Barbara.
Living. — Monterey to Catalina Island (Cooper).
Pleistocene. — San Pedro (Cooper; Arnold): Santa Barbara (Arnold).
Pliocene. — San Pedro (Arnold): San Diego well (Dall): Santa Barbara
(Arnold).
Pliocene. — Sunol, Alameda County (Cooper).
Superfamily VENERACEA.
Family XXVIT. VENERID^.
Subfamily VENERIN^.
Genus Tivela Linl-.
Shell triangular, subequilateral, cuneiform; three to five cardinal teeth in one valve, four to
six in the other; anterior lateral tooth narrow, elongated, compressed; pallial impression with a short
oblique or sometimes horizontal sinus.
Cyfherea is a characteristic species.
ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 143
77. Tivela crassatelloides Conrad.
Cytherea {Trigonella) crassatelloides Con., Jour. Phil. Acad. Sci. , Vol. VII, 1837, p. 253, PI. XIX,
fig. 17. Hinds, Voyage Sulpher, p. 65, PI. XXI, fig. i, 1844.
Donax slidtorum Marve, Linn., Lyst. Conch., pp. 37, 40, PI. IX, fig. 7, 1823. Gray, Index. Test.
Suppl., PI. II i^Donax), fig. 2, 1828.
Cytherea crassatelloides Con., Hanley, Descr. Cat. Rec. Bivalve Shells, p. 106, 1843. Sowerbv,
Thes. Conch., Vol. II, p. 612, PI. CXXVII, figs. 1-3. Reeve, Icon. Conch., Vol. XIV,
PI. I, fig. 3, 1864.
Cytherea slidtorum Gray, Hanley, Descriptive Cat. Rec. Bivalve Shells, p. 106, 1843.
Trigonella crassatelloides Con., Jour. Phil. Acad. Sci., Vol. I, 1849, p. 213.
Trigo/iia crassatelloides CoK., Deshayes, Cat. Conch. Coll. B. M., Part i, p. 46, 1S53.
Trigonia stultorum Gray, Deshayes, Cat. Conch. Coll. B. M., Part i, p. 46, 1853.
Pachydesma crassatelloides CoN., Proc. Phil. Acad. Sci., 1854, p. 121. Carpenter, Brit. Assn-
Rept. 1863, p. 640; =Cytherea solidissima Phil., Gabb, Pal. Cal. Vol. II, p. 96, i86g.
Cooper, 7th. Ann. Rept. Cal. St. Min., 18S8, p. 256. Keep, West Coast Shells, p.
189, fig. 162, 1892.
Tivela crassatelloides CoN., Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 187.
Cytherea {Tivela) crassatelloides Con., Stearns, Proc. U. S. Nat. Mus., Vol. XXI, 1898, pp. 371-
378, PI. XXIII-XXV. Stearns, Nautilus, Vol. XIII, 1899, p. 73.
Shell large, subequilateral, trigonal, depressed, thick; umbones subcentral, small; anterior
extremity shorter and more obtusely rounded than posterior; anterior dorsal margin nearly straight
slopes down obliquely from umbo ; posterior dorsal margin slightly concave in fi-ont of umbo,
slope less than anterior; posterior extremity narrower than anterior; three prominent, thick, cardinal
teeth in each valve, anterior lateral tooth elongated; pallial sinus short, angular.
Dimensions. — Long. 80 mm.; alt. 55 mm.; diam. 30 mm.
The Pleistocene specimens have a tendency toward more central umbones
than do the living forms. This species is distinguishable from the Mactras by its
very thick shell and heavy cardinal teeth. Specimens identified by Dr. Dall.
Common in the upper San Pedro series of San Pedro, Los Cerritos, Long-
Beach, Crawfi.sh George's and Deadman Island; rare in the lower San Pedro series
of Deadman Island. Found also in the Pleistocene of Twenty-sixth Street and Spanish
Bight, San Diego.
Living. — Santa Cruz to San Diego (Cooper).
Pleistocene. — Santa Barbara to San Diego (Cooper): San Pedro; San Diego;
(Arnold).
Genus Callista Poli.
Shell oval, transverse, inequilateral; pallial sinus suboval, profound.
Cytherea erycina Linn, is a characteristic species.
78. Callista newcombiana Gahb.
Lioconcha ne^vcombiana Gabb, Proc. Cal. Acad. Sci., 1865, p. 189; Pal. Cal., Vol. II, p. 96, i86g.
Callista newcombiana Gabb, Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 231. Williamson,
Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 187, PI. XXIII, fig. 4.
Shell thin, trigonally ventricose, polished, marked by minute concentric strize; beaks large,
subcentral; anterior end prominent, narrowly rounded; posterior end a little the widest; base arcuate;
144 CALIFOKNIA ACADEMY OF SCIENCES.
lunule not excavated, but bounded by an impressed line; hinjjje not strong; two small cardinal teeth;
ligamental area excavated, internal.
Dimensions. — Long. 38 mm.; alt. 30 mm.; diam. 10 mm.; length of lunule 12 mm.
This species is distinguisliiible from C. sahdlaphana Carpenter by its promi-
nent impre-sseJ liinule-bounding line, ronnded pallial sinus, and by its coloration in
the living specimens.
Rare in upper San Pedro series at Deadmau Island. Abundant at Twenty-
sixth Street, San Diego.
Living. — Monterey to Catalina Island (Cooper): San Pedro (Williamson).
Pleistocene. — San Pedro (Arnold): San Diego (Coo]ier; Arnold).
Pliocene. — San Diego well (Cooper).
79. Callista subdiaphana Carpenter.
Plate XIII, Fig. 4.
Clevie7ilia subdiaphana Cpr., Brit. Assn. Rept. 1863, p. 640; Proc. Phil. Acad. Sci., 1865, p. 56.
Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 235. Dall, Proc. U. S. Nat. Mus.,
Vol. XIV, 1891, p. 185, PI. VII, figs. 5 and 6.
Shell of medium size, oval, transverse, inequilateral, ventricose, rather thin; beaks small,
incurved; anterior extremity quite sharply angulated about middle of shell; posterior extremity much
longer and wider than anterior and very evenly rounded, projecting furthest a little below the
middle; ventral margin evenly arcuate; surface sculptured by numerous fine, regular, concentric,
incremental lines; neither lunule nor escutcheon, but a faint lunular circumscribing line in front of
umbo; three prominent, sharp, cardinal teeth in each valve, the anterior one being narrower and
longer than the other two; external ligamental groove long, narrow; pallial sinus cuneiform, rather deep.
Dimensions. — Long. 43.5 mm.; alt. 34 mm.; diam. 26 mm.; umbo to anterior extremity 10
mm.; to posterior extremity 33.5 mm.
This sjiecies is very close to Conrad's Dioue anr/usfiformis from the Astoria
Miocene, the external characteristics of both being almost identical. Specimens
identified by Dr. Dall.
Rather common in the Pliocene of Deadman Island and Timm's Point. '
Cooper's " Quarternary " at San Pedro includes the Pliocene, and his specimens
from San Pedro were probably from the Pliocene. The writer has never found
Callista subdiaphana in the Pleistocene of San Pedro or vicinity. The specimen
figured is from the Pliocene of Deadman Island, and is now in the collection of
Delos Arnold.
Living. — South Alaska Coast to San Francisco (Dall).
Pleistocene. — San Pedro to San Diego (Cooper).
Pliocene. — San Diego well (Cooper): San Pedro (Arnold).
80. Callista subdiaphana Carpenter, pedroana, var. nov.
Plate XIII, Fio. 2.
Shell of medium size, subelliptical, transverse, inequilateral, ventricose, rather thin; beaks
small, incurved; anterior extremity evenly rounded, short; posterior extremity faintly biangular,
ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 145
caused by a slight, very oblique truncation across the middle of the extremity; posterior portion of
the ventral line nearly straight; interior the same as in C. siibdiaphana.
Dimensio7is. — Long. 32.5 mm.; alt. 24 mm.; diam. 15 mm.
This variety is very distinct from the typical G. dlapliana, being much narrower,
less ventricose and smaller; and having a shorter, more rounded anterior extremity,
a biangular posterior extremity, and a nearly straight ventral margin.
This variety has been found only in the lower San Pedro series of Dead-
man Island.
Pleistocene. — San Pedro (Arnold).
Subgenus Amiantis Car^^enter.
Fulcra very thick and surface very concentrically rugose.
Type, Cytherea callosa Conrad.
81. Callista (Amiantis) callosa Conrad.
Cytherea callosa Con., Jour. Phil. Acad. Sci., Vol. VII, 1837, p. 252.
Venus callosa Con., Sowerby, Thes. Conch., Vol, II, p. 712, PI. CXIV, figs. 44, 45.
Dosinia callosa Con., Carpenter, Proc. Zool. Soc, 1856, p. 216.
Amiantis callosa Con., Carpenter, Brit. Assn. Rept., 1863, p. 640. G-\bb., Pal. Cal., Vol. II,
p. 96, 1869. Tryon, Syst. Conch., Vol. Ill, p. 178, 1884. ^ Cooper, 7th Ann. Rept. Cal.
St. Min., 1888, p. 266. Keep, West Coast Shells, p. 187, fig. 160, 1892. Cooper,
Bull. No. 7, 1894, Cal. St. Min. Bureau, p. 24.
Meretrix callosa Con., Fischer, Conchologie, p. 1079, 1887.
Callista (Ainiantis) callbsa Con.; =Dio7U' ywbilis RvE. (^fide Dall, Proc. U. S. Nat. Mus. , Vol. XV,
1892, p. 187).
Shell large, suboval, inequilateral, equivalve, heavy; umbones anterior to center, prominent,
recurved; anterior dorsal margin slightly concave; anterior extremity quite sharply rounded near
upper margin; ventral margin evenly arcuate; posterior dorsal margin slightly arcuate; posterior
extremity faintly biangular; surface sculptured by numerous prominent, flat-topped, concentric
ridges, between which are interspaces equal in width to the ridges; lunule distinct, concentrically
striated; hinge heavy; two prominent, strong cardinal teeth; pallial sinus wide, deep and rather
pointed.
Di^nensions. — Long. 66 mm.; alt. 55 mm.; diam. 34 mm.; umbo to anterior extremity
20 mm.; to posterior extremity 46 mm.
Cooper (Seventh Ann. Rept. Cal. St. Min., p. 266) says that this species is like
Tapes montana, described by Conrad from the "Miocene of San Buenaventura."
Specimens identified by Dr. Dall.
Common in the upper San Pedro series of Los Cerritos, but exceedingly rare in
the same horizon of San Pedro. This species is very abundant in the Pleistocene at
Spanish Bight, San Diego.
Living. — Santa Barbara to Lower California (Carpenter).
Pleistocene. — San Pedro (Arnold): San Diego (Arnold).
( 19 ) December 31, 1902.
14G CALIFORNIA ACADEMY OF SCIENCES.
Subfamily Doainina.
Genus Dosinia Scupoll.
Shell orbicular, compressed, concentrically striated, pale, ligament sunk; lunule deep; hinge
like Cylherea; margin even; pallial sinus deep, angular, ascending.
Dosinia discus Reeve ia a characteristic species.
[S. D.] Dosinia ponderosa Gray.
Artemis ponderosa Gray, Analyst, Vol. VIII, 1838, p. 309.
Dosinia ponderosa Gray, H. & A. Adams, Gen. Rec. Moll., Vol. II, p. 432; =Cyiherea gigantea
Sby. ^fide Gabb, Pal. Gal. Vol. II, p. 97, 1869). Cooper, 7th Ann. Rept. Cal. St.
Min., 1888, p. 239.
Shell large, thick, equivalve, subcircular in outline, convex; surface sculptured by many
obsolete, concentric lamellje, and fine, incremental lines; lunule deeply impressed, small, finely
sculptured; beaks small, not elevated; hinge very wide and heavy, with three heavy, cardinal teeth,
the posterior one in the right valve being bifid; ligament long, narrow, sunken.
Dimensions. — Long. 119mm.; alt. 105 mm.; diam. 55 mm.; lunule 15 mm.
Commou in the upper San Pedro series (Pleistocene) of Twenty-sixtli Street,
San Diego.
Living — West Mexican coast to Panama (Carpenter).
Pleistocene. — San Diego (Hemjihill; Arnold).
Pliocene. — Kirker's Pass, Contra Costa County; San Fernando (Cooper):
Stanford University, Santa Clara County (Arnold).
Genus Venus Linne.
Shell thick, ovate, smooth, sulcated, or cancellated; margins minutely crenulated; cardinal
teeth three in each valve; pallial sinus small, angular; ligament prominent; lunule distinct.
Venus verrucosa Linne is a characteristic species.
[S. B.] Venus perlaminosa Conrad.
Mercenaria perlaminosa CoN., Proc. Phil. Acad. Sci., 1855, p. 267. Gabb, Pal. Cal.. Vol. II,
pp. 22, 55, 94; PI. V, fig. 38; PI. XV, fig. 14; 1869. Cooper, 7th Ann. Rept. Cal. St.
Min., 1888, p. 250.
Veyms ke7inerleyi Rye., Icon. Conch. ( Venus'), PI. XII, fig. 41 {^fide Gabb).
"Shell large, thick, rounded, subquadrate, very inequilateral; beaks anterior; anterior end
excavated under the beaks, rounded below; base broadly rounded; posterior end convexly truncated;
cardinal margin slightly convex. Surface closely marked by numerous prominent, recurved,
lamelliform concentric ribs. Lunule marked by an impressed line. Hinge robust. Pallial line
strong, sinus small, oblique, acute at base; muscular scars nearly equal in size; margin minutely
crenulated; the purple color between the pallial line and the base is very persistent." — [Gabb.]
Found in the Pliocene at Packard's Hill, and in the Pleistocene at the bath-
house, Santa Barbara.
ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 147
Subgenus Chione Megerle.
Shell oval, triangular or subcordiform; margins finely crenulated; hinge narrow, solid, with
three teeth in the right valve and two in the left, the anterior tooth longest; ligament narrow; pallial
sinus shallow.
Venus gnidin Bred, is a characteristic species.
82. Venus (Chione) fluctifraga Soiverby.
Plate XIV, Fig. 2.
Vemis fluctifraga Sby., Thes. Conch., 1842-1859.
Chione fluctifraga Sbv., -\-C. callosa Sv,\.\ = Venus cortesi Slo at; = V. giddosula (Desh.) KvE.
{fide Carpenter, Brit. Assn. Rept., 1863, pp. 641, 666). Cooper, 7th Ann. Rept. Cal.
St. Min., 1888, p. 234. Keep, West Coast Shells, p. 187,1892. Williamson, Proc.
U. S. Nat. Mus., Vol. XV, 1892, p. 188.
Shell of medium size and thickness, suboval; surface roughened by radiating rows of
squarish blocks, this condition being caused by wide concentric ridges being cut by radiating
sulcations; spaces between the concentric ridges ornamented by fine, even, incremental lines; lunule
of same sculpture as shell, scarcely differentiated; two prominent teeth and a rudimentary anterior
one in the right valve; pallial sinus quite deep; muscle-impressions elongate-oval.
Diniejisions. — Long. 25 mm.; alt. 21 mm.; diam. 15 mm.
Distinguishable from others of this genus found in these beds by being more
swollen, oval rather than cordiforin in shape, thinner shelled, by the " blocked "
surface, and by the lunule being scarcely differentiated from the rest of the shell.
Specimen identified by Dr. Dall.
Rare in upper San Pedro series of San Pedro ; one specimen, a right valve,
which is figured, and is now in the collection of Delos Arnold. Common in the
Pleistocene at Twenty-sixth Street, San Diego.
Living. — San Pedro to San Diego; Gulf of California (Cooper).
Pleistocene. — Santa Barbara; San Diego (Cooper): San Pedro; San Diego
(Arnold).
83. Venus (Chione) gnidia Broderip £ Sowerby.
Plate XIV, Fig. 7.
Verms gnidia Sby., Gen. Rec. & Fos. Shells ( Venerida:), fig. 7, 1824.
Venus gnidia Brou. & Sby., Zool. Jour., Vol. IV, 1829, p. 364; Zool. Beechey's Voyage, p. 151, PI.
XLI, fig. 3, 1839. Reeve, Syst. Conch., Vol. I, fig. 5, 1841. Carpenter, Brit. Assn.
Rept., 1856, p. 175; 1S63, p. 561.
Chione gnidia Brod. & Sby., Tryon, Syst. Conch., Vol. Ill, p. 176, PI. CXIII, fig. 14, 1884.
Shell large, thick, subcordiform; surface ornamented by several prominent, palmate, concen-
tric frills and numerous squarish, radiating ribs between which are canal-like sulcations of about
equal width with the ribs; the ribs are sharper in outline near the beak and multiply in number both
by division and intercalation as the margin is approached; near the periphery, and also on the anterior
portion of the shell, the ridges become wider and less prominent, and in some cases almost obsolete;
the concentric frills become widely separated in the adult shell; lunule prominent, shows fine laminae
148 CALIFORNIA ACADEMY OF SCIENCES.
of growth which are most prominent when projections of the frills; hinge narrow, solid; three
cardinal teeth in right valve, two in left; ligament narrow; pallial sinus much shorter than lunule;
muscle-impressions distinct.
Dimensio7is. — Long. 98 mm.; alt. 83 mm.; diam. 62 mm.; lunule 18 mm.
This is the largest of the genus found in these deposits and is easily
distinguishable by its size, prominent concentric frills and numerous radiating ribs.
The specimen whose dimensions are given above had twenty-four concentric frills
and about ninety radiating ribs. S^jecimens identified by Dr. Dall.
Rare in the upper San Pedro series of San Pedro, whence the specimen
figured came. This specimen is now in the collection of Delos Arnold.
Living. — -Gulf of California to Panama (Carpenter).
Pleistocene.- — San Pedro (Arnold).
84. Venus (Chione) neglecta Soiverby.
Plate XIV, Fig. 3.
Venus neglecta Sv.N., Thes. Conch., 1842-1849. Carpenter, Brit. Assn. Rept., 1856, p. 306.
Shell of medium size and thickness, suboval; surface ornamented with quite numerous, about
equidistant, undulating, concentric, low frills, and numerous unequal, rounded, radiating ridges^
which are most prominent on the middle of the shell; lunule prominent, ornamented with minute
concentric and radiating sculpture; hinge and pallial sinus are as in C. succinta.
Dhnensiojis. — Long. 29.5 mm.; alt. 24 mm.; diam. 13 mm ; lunule 6 mm.
This species is close to C. succincta, but may be differentiated by its more
oval outline, thinner shell, relatively less diameter, and less prominent but more
numerous concentric frills. Specimen identified as " probably 0. neglecta " by Dr. Dall.
Rare in ujjper San Pedro series of San Pedro and Los Cerritos. The specimen
figured is from the upper San Pedro series at San Pedro, and is now in the collection
of Delos Arnold.
Living. — Gulf of California and Central America (Carpenter).
Pleistocene. — San Pedro (Arnold).
85. Venus (Chione) simillima Sowerby.
Venus simillima Sbv., Thes. Conch., p. 708, PI. CLIII, figs. 17, 18, 1842-1859.
Chione simillima Sbv., Carpenter, Brit. Assn. Rept., 1863, p. 641. Cooper, 7th Ann. Rept. Cal.
St. Min., 1888, p. 234. Keep, West Coast Shells, p. 186, 1892. Williamson, Proc.
U. S. Nat. Mus., Vol. XV, 1892, p. 188.
Shell of medium size, thick, subcordiform ; surface ornamented by numerous slightly
crenulated, refle.xed, concentric frills, which grow closer and closer together as the periphery is
approached, and by about twenty bifurcated, radiating ridges, which are largest in the middle of the
shell, becoming obsolete anteriorly and posteriorly, and increasing in number, but fading out as the
periphery is approached; lunule prominent, ornamented with incremental lamina; hinge narrow;
only two prominent cardinal teeth on each valve; pallial sinus very shallow; margin crenulated.
Dimensions. — Long. 40 mm. ; alt. 35 mm. ; diam. 25 mm. ; lunule 9 mm.
ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 149
Distinguishable from others of this genus occurring in these deposits by the
even, close, lattice-like sculpture. Specimens identified by Dr. Dall.
Common in upper San Pedro series at San Pedro, Los Cerritos, Crawfish
George's, and Deadman Island; rare in the lower San Pedro series at Deadman
Island. Found also in the Pleistocene at Twent3'--sixth Street, San Diego.
Living. — Monterey to Lower California (Carpenter).
Pleistocene. — Santa Barbara to San Diego (Cooper): San Pedro; San Diego
(Arnold).
86. Venus (Chione) succincta Valenciennes.
Plate XIV, Fig. 1.
Veiius sticcincta Val., Humb. & Bonpl., Obs. sur Zool., p. 219, PI. LXVIII, fig. i, 1833.
Chione succincta Val. =C califoniiensis Brod. =C mdtalli Con. ^fide Carpenter, Brit.
Assn. Rept., 1863, p. 641.)
Chione succiticla Val. = Venus californica CoN. = V. nuttalli CoN. = V. laynellifera Con.
(Wilkes' Exped. and Jour. Conch., 1865; not V. lamelli/era Cofi.,]onT. Phil. Acad.,
Vol. VII, viW\ch ^ Tapes siajninea var. ruderaia) =V. brevilineata Con. =^Chione
brevilineata Con. = F. securis Shum. (yfide Gabb, Pal. Cal., Vol. II, p. 94, 1869).
Cooper, 7th Ann. Rept Cal. St. Min., 1888, p. 234. Keep, West Coast Shells, p. 187,
fig. 159, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 188.
Shell of medium size, thick, subcordiform; surface ornamented by several about equidistant,
slightly reflexed, low, concentric frills and numerous rounded, radiating ridges, most prominent on
the middle of the shell, which increase by intercalation and become flattened and less prominent as
the periphery is approached; lunule prominent, ornamented by both incremental laminae and
rounded, radiating ridges; hinge narrow; two prominent cardinal teeth in each valve; pallial sinus
very shallow; margin crenulated.
Dimensions. — Long. 55 mm.; alt. 50 mm.; diam. 32 mm.; lunule 13.5 mm.
The specimen whose measurements are given was the largest of the specimens
examined. Distinguishable by the equidistant concentric frills, low, rounded,
radiating lines, and radiating lines on the lunule.
Rather common in upper San Pedro series of San Pedro, Los Cerritos,
Crawfish George's and Deadman Island. Found also in the Pleistocene of Barlow's
ranch, Ventura, and Twenty-sixth Street, San Diego. The specimen figured is
from the upper San Pedro series at San Pedro, and is now in the collection of
Delos Arnold.
Living. — Santa Barbara to San Diego; Mexico; South America (Cooper).
Pleistocene. — Santa Barbara to San Diego (Cooper): San Pedro (Arnold).
Pliocene. — Seven Mile Beach, San Mateo County; San Fernando (Cooper).
Miocene. — Oregon; Martinez; San Pablo; Griswold's, San Benito County;
Foxin's, Santa Barbara County; Santa Monica (Cooper).
Superfamily TAPETIN.E.
Genus Tapes Megerle.
Shell oblong, umbones anterior; margins smooth; teeth three in each valve, more or less
bifid; pallial sinus deep, rounded.
Ihpes litterata Linne is a characteristic species.
150 CALIFORNIA ACADEMY OF SCIENCES.
87. Tapes laciniata Carpenter.
Plate XIV, Fig. 5.
Ta/>es laciJiiata Cpr., Brit. Assn. Rept., 1863, p. 641; Jour, de Conch., Vol. XII, 1865, p. 136
Keep, West Coast Shells, p. 186, 1892. Williamson, Proc. U. S. Nat. Mus., Vol.
XV, 1892, p. 188.
Shell large, oval, swollen, thick, but brittle; surface net-like, caused by prominent, thick
rounded, concentric frills, and numerous rounded, radiating ridges; margin smooth; hinge and
interior parts as in T. staminea.
Dimensions. — Long. 80 mm.; alt. 6S mm.; diam. 56 mm.
Resemble.? T. staminea in otitliiie, but is much larger, heavier, ami more
brittle, and has a much more decided cancellate sculpture.
Rare in upper San Pedro series at San Pedro, but rather common at Los
Cerritos in the same horizon. The specimen figured is from the upper San Pedro
series at Los Cerritos, and is now in the collection of Delos Arnold.
Living. — Monterey to San Diego (Carpenter).
Pleistocene. — San Pedro (Arnold).
88. Tapes staminea Conrad
Plate XIV, Fig. 4.
Venus slaminea CoN., Jour. Phil. Acad. Sci., Vol. VII, 1837, p. 250, PI. XIX, fig. 15,
Tapes staminea Con., Carpenter, Brit. Assn. Rept., 1S63, p. 641; ^ V. lamelli/era Con., (Jour. Phil.
Acad., Vol. VII, 1837; not of Wilkes' Exped.); = T. diverstim Co'N.; =T. /ineafi/m
Con.; =Ve7ius rigida Gld. (/(/cGabr, Pal. Cal., Vol. II, p. 97, 1869). Cooper, 7th
Ann. Rept. Cal. St. Min., 1888, p. 266. K5EP, West Coast Shells, p. 185, fig. 158,
1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 188.
Shell of medium size and thickness, suboval, convex; surface sculptured with numerous, crowd-
ed, rounded, radiating ridges, and concentric lines, which are most prominent on anterior end; nolunule;
margin sometimes crenulated; hinge narrow; ligament narrow, long; three teeth in each valve;
posterior two in right valve and middle one in left valve bifid; pallial sinus long, rounded; muscle-
impressions not sunken.
Dimensions. — Long. 50 mm.; alt. 42.5 mm.; diam. 30 mm.
This is a variable species, the shape of the shell and the sculpture varying in
different individuals. The form above described is the most common in tlie San
Pedro beds. Specimens identified by Dr. Dall.
Rare in the lower San Pedro series at Deadman Island and San Pedro;
common in the upper San Pedro series at Deadman Island, San Pedro, Los Cerritos,
Crawfi.sh George's and Long Beach. Tbe specimen figured is from the upper San
Pedro series of San Pedro and is now in tbe collection of Delos Arnold. Found in
the Pliocene at Pacific Beach and Russ School; and in the Pleistocene at Twenty-
sixth Street and Spanish Bight, San Diego.
Living. — Straits of Fuca to Lower California (Cooper).
Pleistocene. — Santa Barbara to San Diego (Cooper): San Pedro; San Diego
(Arnold).
ARNOLD — THE PALEONTOLOGY AND STEATIGKAPHY OF SAN PEDRO. 151
Pliocene. — Santa Rosa; Twelve Mile House, San Mateo County; Kirker's
Pass, Contra Costa County; Monterey; San Fernando (Cooper) ; San Diego (Arnold).
Miocene. — West of San Jose; Foxin's, Santa Barbara County (Cooper).
89. Tapes tenerrima Carpenter.
Plate XIV, Fi<;. 6.
Tapes lenerrima Cpr., Proc. Zool. Soc, 1856, p. 200; (jun.) ^=Vcnus rigida Gld., pars, {fide
Carpenter, Brit. Assn. Rept., 1863, p. 641.) Gabb, Pal. Cal, Vol. II, p. 97, 1869.
Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 267. Keep, West Coast Shells,
P- 157. fig, 136, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 188.
Shell large and thin, oval, convex; surface sculptured by numerous low, sharp, concentric
frills, and numerous tine, rounded, crowded, radiating lines, these latter lines being almost obsolete
in some specimens; margin smooth, hinge long and narrow; three teeth in each valve, the anterior
two in the right valve and the middle one in the left valve prominently bifid; pallial sinus very deep
and rounded; no lunule.
Dimensions. — Long. 86 mm.; alt. 63.5 mm.; diam. 34 mm.
This is the largest and finest Tapnn found in these deposits, and is easily
distinguishable by its largo, thin, shallow shell and regular, oval outline. Specimens
identified by Dr. Dall.
Rather rare in the upper San Pedro series of San Pedro, Los Cerritos, Crawfish
George's and Deadman Island. The specimen figured is from the upper San Pedro
series at San Pedro, and is now in the collection of Delos Arnold. Found also in the
Pleistocene at Barlow's ranch, Ventura, and at Spanish Bight, San Diego.
Living. — Straits of Fuca to San Diego (Cooper).
Pleistocene. — Santa Barbara (Cooper): San Pedro; San Diego; Ventura
(Arnold).
Pliocene. — Santa Barbara (Cooper).
Genus Saxidomus Conrad.
Shell transversely oval, inequilateral, solid, ventricose; without lunule; umbones tumid;
teeth three or four, inequal, narrow, the central bifid; ligament very thick, elongated; muscular
impressions oval or rouuded, nearly equal; pallial sinus large, elongated, horizontal.
Type, Saxidomus nuttallii (Con.).
90. Saxidomus aratus Gould.
Saxidomus araius Gld., Otia Conch., p. 168, 1862. Carpenter, Brit. Assn. Rept., 1863, p. 641.
Keep, West Coast Shells, p. 183, 1892. Williamson, Proc. U. S. Nat. Mus., Vol.
XV, 1892, p. 188.
Tapes gracilis Gld., Pac. R. R. Rept, Vol. V., p. 333, PI. XIX, fig. 20, 1853.
Saxidomus gracilis, Gld., = Venus maxima Phil, (fide Gabb, Pal. Cal., Vol. II, 1869, p. 98).
Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 263.
152 CALIFORNIA ACADEMY OF SCIENCES.
Shell large, transversely elliptical, equivalve, inequilateral, convex, thick; umbones turned,
anterior to middle; anterior end evenly rounded; posterior end much more produced, having a slight
tendency toward biangulation; surface sculptured with strong, elevated concentric lines, which in the
adult often have the prominence of concentric lamina; ligamental area external, wide, long, strong;
cardinal teeth four, anterior one long and narrow; pallial sinus long, rather narrow, rounded extremity
near middle of shell and impressed against the posterior adductor scar.
Dimens/o/is. -^hong. 89 mm.; alt. 62 mm.; diam. 44 mm.; umbo to anterior extremity
30 mm. ; to posterior extremity 59 mm.
Specimens identified by Dr. Dall.
Rare in the lower San Pedro series of Deadman Island; common in the upper
San Pedro series at Deadman Island, Crawfish George's, Los Cerritos and San Pedro.
Found also in the Pleistocene at Barlow's ranch, Ventura, and at Twenty-sixth Street,
San Diego.
Living. — Baulines Bay to San Diego (Cooper).
Pleistocene. — Santa Barbara to San Diego (Cooper) : San Pedro; Blakeley,
near Seattle, Washington (Arnold) : San Diego; Ventura (Arnold).
Pliocene. — Kirker's Pass, Contra Costa County; Twelve Mile House, San
Mateo County; Santa Barbara, San Fernando (Cooper).
Miocene. — Martinez; Walnut Creek, Contra Costa County; Santa Cruz; Santa
Inez, Santa Barbara County; Santa Monica (Coojier).
Subfamily GEMMIN.E.
Genus Psephis Carpenter.
Shell thin, rounded or quadrangular, somewhat inflated; pallial sinus small; three elongated,
thin, cardinal teeth in each valve.
Psephis lordi (Baird) is a characteristic species.
91. Psephis salmonea Carpenter.
Psephis salmonea CpR., Brit. Assn. Rept., 1863, p. 641. Cooper, 7th Ann. Rept. Cal. St. Min.,
1888, p. 261.
Shell very small, ovate trigonal, inequilateral; posterior end evenly rounded; posterior
dorsal margin rounded; in other ways resembles P. ianlilla.
Dimensions. — Long. 5 mm.; alt. 4 mm.; diam. 2.5 mm.
Distinguishable from P. tantilla by smaller size and less trigonal outline.
Specimens examined showed no coloration.
Rare in the lower San Pedro series at Deadman Island and San Pedro.
Found also in the Pliocene at Packard's Hill, and in the Pleistocene at the bath-
house, Santa Barbara.
Living. — Catalina Island (Cooper; Arnold): 10 fathoms (Arnold, 1901).
Pleistocene. — Santa Barbara (Cooper): San Pedro; Santa Barbara (Arnold).
Pliocene. — Santa Barbara (Arnold).
ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 153
92. Psephis tantilla Gould.
Plate XIII, Fig. 5.
Venus tantillus Gld., Bost. Jour. Nat. Hist., Vol. VI, 1853, P- 906, PI. XV, fig. 10.
TrigoJiJa ianiilla Gld., Carpenter, Proc. Zool. Soc, 1856, p. 201.
Psephis tantilla Q\.v>., Carpenter, Brit. Assn. Rept., 1S63, p. 640; =Venus rysonia Gabb {Jide
Gabb. Pal. Cal., Vol. II, p. 96, i86g). Cooper, 7th Ann. Rept. Cal. St. Min., 1888,
p. 261. Keep, West Coast Shells, p. 186, 1892. Williamson, Proc. U.S. Nat. Mus.,
Vol. XV, 1S92, p. 188.
Shell small, ovate-trigonal, inequilateral; beaks acute, slightly anterior to center; surface
smooth or faintly waved with distant, concentric furrows; the dorsal margins are nearly straight, and
meet at the apex in a right angle, but the posterior side is a fourth longer than the anterior; the
anterior basal angle is well rounded, while the posterior is acute; basal margin gently curved; hinge
area short, wide; three prominent, elongated cardinal teeth in each valve.
Dimensions. — Long. 10 mm.; alt. 8 mm.; diam. 4.9 mm.
Somewhat re.sembles a very small Tivela crassaielloides. Some show original
purple spot on posterior end. Specimens identified by Dr. Dall.
Rather common in the lower San Pedro series at Deadraan Island and San
Pedro; rarer in the upper San Pedro series at Deadman Island, Los Cerritos, and
San Pedro. The specimen fii^ured is from the lower San Pedro series at Deadman
Island and is now in the collection of Delos Arnold.
Living. — Straits of Fuca to Catalina Island (Cooper).
Pleistocene. — Santa Barbara (Cooper): San Pedro (Arnold).
Family XXVIII. COOPERELLID.E.
Genus Cooperella Carpenter.
Shell small, thin, smooth, or concentrically striate or undulate, equivalve, nearly equilateral,
with entire margins; ligament long; resilium short; hinge plate narrow, carrying two right and three
left subumbonal, divaricating, short cardinal teeth; laterals none; pallial line narrow, with an
ample sinus.
Type, CEdalia suhdiaphnna (Carpenter).
93. Cooperella subdiaphana Carpenter.
Plate XIII, Fig. ].
CEdalia subdiaphana Cpr., Brit. Assn. Rept., 1863, p. 639; Jour, de Conch., Vol. XII, 1865, p. 134.
QLdali7ia subdiaphana Cpr., Proc. Cal. Acad. Sci., Vol. Ill, 1866, p, 208.
Cooperella subdiaphana Cpr., Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 5, 1900, p. 1062.
Shell small, subquadrangular, subequilateral, convex, very thin and fragile; posterior extremity
evenly rounded; anterior extremity rounded near base; surface smooth except for incremental lines;
beaks slightly raised, sharp, prominent; two narrow, tall, sharp, bifid teeth in left valve, three in
right; pallial sinus very large.
Dimensions. — Long. 12 mm.; alt. 9 mm.; diam. 6 mm.
( 20 ) January 8, 1903.
154 CALIFORNIA ACADEMY OF SCIENCES.
Externally this species mucli resembles a Kellia, but may be distinguished by
the pallial sinus and hinge teeth. Specimens identified by Dr. Dall.
Two left valves from lower San Pedro series of Deadman Island, one of which
is figured, and is now in the collection of Delos Arnold. Rather common in the
Pleistocene at Spanish Bight, San Diego.
Living. — Vancouver Island to Todos Santos Bay (Dall).
Pleistocene. — Sau Pedro (Dall; Arnold): San Diego (Arnold).
Family XXIX. PETRICOLID.E.
Geuus Petricola Lamarck.
Shell oval or elongated, thin, tumid, anterior side short; hinge with generally three teeth in
each valve, the external often obsolete; pallial sinus deep.
Type, Venus lapicida (Chemn.).
Section Petricola Larnarch a. s.
Shell ovate, with a short or moderately wide pallial sinus, the radial sculpture more or less
divaricate or zigzag.
Type, Petricola lapicida (Gmel.).
94. Petricola carditoides Conrad.
Saxicava carditoides CoN., Jour. Acad. Nat. Sci. Phil., Vol. VII, 1837, p. 255, PI. XX, fig. 8.
Petricola carditoides Con. , Jour. Acad. Nat. Sci. Phil., 1849, p. 213. Carpenter, Proc. Zool. Soc,
1856, p. 214; =/". califorjiica CoN. ^P. cylindracea Desh. =/*. arcuata Desh. ^P.
gibba MiDD. (7?^^ Carpenter, Brit. Assn. Rept., 1863, p. 641). Cooper, 7th Ann.
Rept. Cal. St. Min., 1888, p. 258. Keep, West Coast Shells, p. 183, 1892. William-
son, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 189. Dall, Trans. Wagner Inst. Sci.,
Vol. Ill, Part 4, 1898, p: 835; Part 5, 1900, p. 1059.
Shell of medium size and variable outline, generally oblong-oval, conve.x, thick; surface
ornamented with fine, concentric, incremental lines, which sometimes form irregular ridges, and by
fine, wavy, radiating lines; hinge-area prominent; three cardinal teeth in each valve, the anterior one
smallest; margin smooth.
Dimensio7ts. — Long. 28 mm.; alt. 25 mm.; diam. 16 mm.
A variable form which is recognized, however, by its sculpture, prominent
teeth and thick shell. Often found in holes in the pebbles and boulders comprising
the conglomerate in this formation. Specimens identified by Dr. Dall.
Not uncommon in the lower San Pedro series at Deadman Island; and in
the upper San Pedro series at Deadman Island, Los Cerritos, Crawfish George's, and
San Pedro. Found also in the Pleistocene at Spanish Bight, San Diego.
Living. — Sitka to San Diego (Cooper).
Pleistocene. — San Pedro to San Diego (Cooper): San Pedro; San Diego
(Arnold).
ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 155
Section Rupellaria Fleurian.
Shell inflated and rounded in front, attenuated and more compressed behind; sculpture
chiefly radial ; stronger anteriorly.
Type, Petricola lithophaga (Retzius).
95. Petricola (Rupellaria) lamellifera Conrad.
Veyms lamellifera Con., Jour. Phil. Acad. Nat. Sci., Vol. VII, 1837, p. 257, PI. XIX, fig. 19.
Veneriipis cordieri v^r. B, Desh., B. M. Catal. Ven., p. 191, No. i.
Petricola cordieri D^sn., Rev. Zool. Soc. Cur., 1839, p. 358; Mag. Zool., PI. XVIII.
Rtipellaria lamellifera Con., Carpenter, Proc. Zool. Soc, 1856, p. 214. Carpenter, Brit. Assn.
Rept., 1863, p. 641. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 262. Keep,
West Coast Shells, p. 1S3, fig. 156, 1892. Williamson, Proc. U. S. Nat. Mus., Vol.
XV, 1892, p. 184.
Shell of medium size, convex, equivalve, inequilateral, thick; beaks anterior to middle,
marginal, not much elevated, turned slightly forward ; anterior extremity evenly rounded ; posterior
extremity widely truncated; surface sculptured by ten or twelve lamelliform, concentric, slightly
reflected ribs, and rather faint radiating sulcations; lunule indistinct, sculptured; ligament rather short;
hinge strong, with two bifid and one single tooth in each valve; pallial sinus deep, narrow, pointed;
muscle-impressions distinct, oval.
Dimensions. — Long. 26 mm.; alt. 21.5 mm.; diam. 16 mm.
This species resembles Petricola carditoides, but is distinguishable by the
prominent concentric lamellar frills. Like P. carditoides this shell bores in the
rocks; and all of the specimens obtained were broken from the shale pebbles in
the upper San Pedro gravels of Deadman Island.
Living. — Farallon Islands to San Diego (Cooper).
Pleistocene. — Santa Barbara (Cooper): San Pedro (Arnold).
Section Petricolaria Stoliczka.
Shell elongated, pholadiform, thin; hinge-teeth protracted, slender; pallial sinus deep.
Type, Petricola pholadiformis (Lane).
96. Petricola (Petricolaria) denticulata Sowerby.
Petricola detiiiculata Sby., Thes. Conchyliorum (?).
Petricola pedroana CoN., Pac. R. R. Rept., Vol. V, p. 324, PI. Ill, fig. 24, 1856. Gabb, Pal. Cal.,
Vol. II, p. 119, 1869.
Petricola denticulata Sby., Carpenter, Brit. Assn. Rept., 1856, pp. 244, 297.
Cypricardia pedroana Con., Cooper, Bull. No. 4, Cal. St. Min. Bureau, 1894, p. 25.
Shell small, elongate-oval, convex, thin; surface sculptured by fine, concentric, incremental
lines, and numerous, undulating, radiating ridges, which are most prominent on the anterior portion
of the shell; anterior end short and rounded; teeth small; pallial sinus deepi
Dimetisiotis. — Long. 20 mm.; alt. X2 mm.; diam. 10 mm.
156 CALIFORNIA ACADEMY OF SCIENCES.
Distinguishable from P. carditoides by its smaller size, narrower form, thinner
shell, and coarser sculpture. Specimens of this same species in the State Museum
collection at the University of California, Berkeley, are labeled P. cognata Adams.
Specimens identified by Dr. Dall.
Rare in the lower San Pedro series at Deadman Island, and the upper San
Pedro series at Los Cerritos and San Pedro.
Living. — Mazatlan to Peru (Carpenter).
Pleistocene. — San Pedro (Arnold; Blake.)
Pliocene (?). — Los Angeles City (Williamson).
97. Petricola (Petricolaria) cognata C. B. Adams.
Pelrkola cognala C. B. Ads., Cat. Panama Shells; Ann. N. Y. Lye. Nat. Hist., Vol. V, 1852,
p. 510. Cpr., Brit. Assn. Rept., 1856, p. 363; Proc. Zool. Soc, 1863, p. 367.
Shell of medium size, much elongated, transverse, conve.x, thin, equivalve; beaks small, near
anterior e.xtremity, turned forward, slightly elevated; anterior extremity short, evenly, pointedly
rounded; posterior extremity long, evenly, pointedly rounded; surface of shell, anterior to a line
running obliquely backwards from the beaks, sculptured by ten or eleven prominent, narrow,
squamosely spined, radiating ridges; surface posterior to this line ornamented by finer radiating lines;
rather prominent incremental lines over the whole surface; hinge of left valve consists of a curved,
saddle-shaped process of two teeth, one of which is bifid; hinge of right valve smaller and straighter
with less prominent division of teeth.
Dimensions. — Long. 36 mm.; alt. 10.5 mm.; diam. 10 mm.; beaks to anterior extremity
6 mm.; to posterior extremity 30 mm.
The line of demarkation between the fine and prominent radiating sculpture
in this species is not marked as in the Plioladidre. Distinguishable from P. denticnlafa
by more prominent sculpture anteriorly, longer shell, more prominent hinge-teeth and
more anterior beaks. P. cognata is close to the Atlantic P, plioladiformis. Some
authorities, notably Carpenter, unite the two forms.
Rare in the upper San Pedro series at the lumber yard at San Pedro and
at Deadman Island.
Living. — San Pedro to Panama (Dall, m.ss.).
Pleistocene. — San Pedro (Arnold).
Superfamily TELLINACEA.
Family XXX. TELLINID^.
Genus Tellina Linne.
Subgenus Mcerella Fiiichei-.
Shell small, compressed, hardly folded, acute behind, rounded in front, with feeble, concentric
sculpture; left laterals obsolete; no interior radii; the sinus long, coalescent with the pailial
line below. ^
Type, Pellina donncina (Linnr).
ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 157
98. Tellina (Mcerella) salmonea Carpenter.
Plate XIII, Fic. 7.
Mtrr a salmonea Qvsi., Brit. Assn. Rept., 1863, p. 639; Ann. & Mag. Nat. Hist., 3id Ser., Vol. IV,
1864, p. 423. Keep, West Coast Shells, p. 196, 1892.
Shell small, suboval, convex, equivalve, inequilateral, thin; umbones anterior to center,
small, sharp; anterior extremity short, rounded; posterior dorsal margin straight; posterior extremity
acutely rounded; ventral margin evenly arcuate; surface glossy, ornamented with fine, concentric,
incremental lines, and obsolete radiating scratches; cardinal tooth small, bifid; no lateral teeth;
pallial sinus long, broad; one faint, internal, submarginal, posterior, radiating ridge.
Dimensions. — Long. 11 mm.; alt. 8 mm.; diam 4.2 mm.; umbo to anterior extremity 3 mm.;
to posterior extremity 8 mm.
Resembles Bonax, but is mucb thinner, more evenly rounded anteriorly,
has no lateral teeth, and is not crenulated on the interior of the margin. Specimen
identified by Dr. Dall.
Not uncommon in the lower San Pedro series at Deadman Island, whence the
specimen figured came. This specimen is now in the collection of Delos Arnold.
Living. — Vancouver to Monterey (Carpenter).
Pleistocene. — San Pedro (Arnold).
Subgenus Angulus Megevle.
Shells elongated, generally small, compressed, with the posterior end angularly pointed and
not twisted; the surface smooth or with fine concentric sculpture; nymphs short and prominent, the
ligament short; hinge with a single adjacent lateral well developed in the right valve anteriorly;
internally a thickened ray passes from the umbo just behind the anterior adductor scars, and one or
two narrower similar rays in front of the posterior adductors; sinus largely coalescent with the pallial
line below.
Type, Tellina lanceolata Linnc'.
99. Tellina (Angulus) button! Dull.
Plate XVI, Figs. 1 and 2.
Tellina (Oudardia) buttoni Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 5, 1900, p. 1036,
PI. XLVII, fig. 18.
Angtilus modeslus of California collectors (not of Carpenter).
Tellina (Angulus) var. obtusus Cpr. (noi Tellina obtusa Sowerby.)
f Tellina pedroa7ia Con., Pac. R. R. Rept., Vol. V, p. 323, PI. Ill, fig. 17, 1855.
? Macoma pedroana Con., Gabb, Pal. Cal., Vol II, pp. 94, 124, 1S69. Cooper, 7th Ann. Rept. Cal.
St. Min., 1888, p. 248.
Shell small, oblong, subtriangular, compressed, thin; umbones slightly posterior to center;
anterior dorsal margin evenly arcuate; anterior extremity quite acutely rounded, produced furthest
near base; ventral line subrectilinear; posterior extremity cuneiform, abruptly truncated at end near
base; surface sculptured by fine, concentric, incremental lines; one prominent cardinal tooth in each
valve; one sharp, anterior lateral tooth in right valve; pallial sinus large, does not quite reach to
anterior muscle-impression; anterior, radiating callus passes from umbo just posterior to the anterior
muscle-impression.
Dimensions. — Long. iS mm.; alt. 10.5 mm.; diam. 4 mm.; umbo to anterior extremity
II mm.; to posterior extremity 7 mm.
158 CALIFORNIA ACADEMY OF SCIENCES.
A note accompanying one of these specimens says, "Tellina striata Hanley.
This specimen was identified by Dr. Dall." Upon further examination Dr. Dall
pronounced them to be Anguhis buttoni.
Found in lower Ban Pedro series of Deadman Lsland and San Pedro bluffs;
and in the upper San Pedro series of Deadman Island, San Pedro, Crawfish George's,
and Los Cerritos. Found also in the Pleistocene at Barlow's ranch, Ventura. The
specimen figured is from the upper San Pedro series at San Pedro, and is now in
the collection of Delos Arnold.
Living. — West Coast.
Pleistocene. — San Pedro; Ventura (Arnold).
100. Tellina (Angulus) bodegensis Hinds.
Plate XV, Fig. 8.
Tellina bodege7isis Hds., Voy. Sulphur, p. 67, PI. XXI, fig. 2, 1844. Carpenter, Brit. Assn.
Rept., 1863, p. 639; =7! emacerata Con. {^fide Gabb, Pal. Cal., Vol. II, p. 92, 1869).
Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 267. Keep, West Coast Shells, p. 197,
fig. 169, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 185. Dall,
Trans. Wagner Inst. Sci. , Vol. Ill, Part 5, 1900, p. 1029.
Shell of medium size, elongated, narrow-ovate, rather thick; umbones posterior to center
and pointing posteriorly; anterior portion of shell evenly rounded, the dorsal and ventral lines being
nearly parallel; posterior dorsal margin depressed back of umbo, running off quite obliquely to a line
which truncates the posterior end near the base; basal posterior angle nearly a right angle; basal
line nearly straight; a prominent bifid cardinal tooth on each valve; pallial sinus long and narrow;
generally thickened anteriorly.
Dimeyisions. — Long. 48 mm.; alt. 25 mm.; diam. 12 mm.; umbo to anterior extremity
27 mm.; to posterior extremity 21 mm.
Specimen identified by Dr. Dall.
Common in the upper San Pedro series at San Pedro, Los Cerritos, Crawfish
George's, Deadman Island, and Long Beach; rarer in the lower San Pedro series at
Deadman Island and San Pedro. Found also in the Pleistocene at Spanish Bight,
San Diego. The specimen figured is from the upper San Pedro series at San Pedro,
and is now in the collection of Delos Arnold.
Living. — Straits of Fuca to San Diego; Japan (Cooper).
Pleistocene. — San Pedro to San Diego (Cooper): San Pedro; San Diego
(Arnold).
Miocene. — Oregon; Walnut Creek, Contra Costa County (Cooper).
loi. Tellina (Angulus) idae Dall.
Plate XV, Fig. 7.
Tellina idaD\-L\., Proc. U. S. Nat. Mus., Vol. XIV, 1891, p. 183, PI. VI., fig. 3; PI. VII, figs.
I, 4. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 185. Cooper, Bull.
No. 4, Cal. St. Min. Bureau, Part 3, 1894, p. 32.
Tellinella, Cooper, No. 63, Geol. Cat., 1867.
ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 159
Shell of medium size, ovate-triangular, moderately elongate, compressed, thin; beaks sub-
central, small, pointed, prominent; anterior extremity evenly rounded; posterior dorsal slope steeper,
rectilinear, obliquely truncate at its termination; ventral margin moderately incurved at flexure,
which is narrow, but well marked, and extends out into a prominent beak at the extremity of the
shell; a prominent, narrow, submarginal, flexural ridge extends from beak to posterior extremity;
surface sculptured with numerous, regular, sharp, elevated, concentric, incremental lines; hinge area
broad and strong; one prominent cardinal tooth in each valve, which is bifid in right valve; one
anterior lateral in right valve; ligamental area prominent, long; pallial sinus very large, extending
nearly to anterior adductor scar.
Dimensions. — Long. 62 mm.; alt. 37 mm.; diam. 10 mm.
Distinguishable from T. bodegensis by larger, broader shell, more central, less
curved beaks, much more prominent flexural ridge, posterior beak and incurved base
line, much stronger, broader hinge, and much larger pallial sinus. Distinguishable
from 7\ rubescens by more extended, beaked posterior extremity, flexural ridge,
straight beaks, and much stronger hinge, especially in the ligamental area. Speci-
mens identified by Dr. Dall.
One valve found in the upper San Pedro series at Los Cerritos, which is
figured herewith, is now in the collection of Delos Arnold.
Living. — Catalina Island, 16 to 38 fathoms, young (Dall): San Pedro Bay;
Long Beach (Shephard).
Pleistocene. — San Pedro (Arnold).
102. Tellina (Angulus) rubescens Hanley.
Plate XV, Fig. 9.
Tellina rubescens Hanl., Carpenter, Brit. Assn. Rept., 1856, p. 302.
Shell of medium size, ovate-triangular, compressed, thin; beaks posterior, small, sharp,
turned toward the rear; anterior dorsal margin evenly but slightly arcuate to near extremity, where
it turns off quite abruptly, giving an evenly rounded end, which is most produced below the middle;
posterior dorsal slope steeper, rectilinear; posterior extremity truncated, with a rounded right angle
at base; basal margin nearly rectilinear from posterior angle to within one-third length of shell from
anterior end; a prominent angular ridge extends from beak to posterior basal angle; surface sculp-
tured by regular alternating concentric bands and distinct sulcations; sculpture less regular posterior
to angular ridge; hinge-area small; right valve with two cardinal teeth, posterior one bifid; one
posterior lateral tooth at lower end of ligamental area in right valve; pallial sinus large, arcuate
upwards near middle and extending nearly to anterior adductor scar.
Dimensions. — Long. 43 mm.; alt. 26 mm.; diam. 10 mm.; beak to anterior extremity
23 mm.; to posterior extremity 20 mm.
Distinguishable from 2\ bodegensis by mucli broader shell, less oblique trunca-
tions, greater convexity, more regular and coarser sculpture, stronger hinge, posterior
lateral tooth, and much larger pallial sinus, which extends ahnost to anterior adduc-
tor. Distinguishable from 2\ idre by less produced and unflexed posterior portion,
basal posterior angle, and rectilinear ventral margin, weaker hinge, and posteriorly
bent beaks. This species seems to lie between 2\ idoB and ?'. bodegensis in many
respects, having the large sinus of the one and the general, though much broader,
outline of the other. Specimen identified by Dr. Dall.
160 GALIFOKNIA ACADEMY OF SCIENCES.
Rare in upper San Pedro series of San Pedro; one perfect right valve, which
is figured, is now in the collection of Delos Arnold.
Living. — Pananaa; Central America (Carpenter).
Pleistocene. — San Pedro (Arnold).
Genus Metis H. <£• A. Adams.
Shell slightly inequivalve, suborbicular, compressed; valve sillonated; posterior flexuosity
submedian; no lateral teeth.
Tellina meyeri Phil, is a characteristic species.
103. Metis alta Conrad.
Tellina alia Con., Jour. Phil. Acad. Nat. Sci., Vol. VII, 1837, p. 258; (not T. alia Con., Foss. Tert.
Form., Vol. I, No. 4, p. 41, 1833. Hanley, Thes. Conch., Vol. I, p. 332, PL LXII,
fig. 200, 1847.
Lutricola alia Con., Carpenter, Brit. Assn. Rept., 1863, p. 639; =Arcopag7a medialis Con. (^fide
Gabb, Pal. Cal., Vol. II, p. 92, 1S69), Cooper, 7th Ann. Rept. Cal. St. Min., 1888,
p. 247. Keep, West Coast Shells, p. 197, 1892. Williamson, Proc. U.S. Nat. Mus.,
Vol. XV, 1892, p. 186.
Alelis alia Con., ^ Scrobicularia biangiilata Cpr. {,fide Dall, Trans. Wagner Inst. Sci., Vol. Ill,
Part 5, igoo, p. 1044).
Shell large, suboval, approaching to subcircular, ventricose, of medium thickness; beaks
central; anterior extremity obtusely rounded ; posterior side of the deeper valve biangulated; the
opposite valve with an angular groove; surface sculptured by numerous prominent lines of growth
and by numerous minute, radiating lines; cartilage-pit more vertical than oblique; muscle-
impressions large.
Dimensions. — Long. 75 mm.; alt. 65 mm.; diam. 40 mm.
Resembles a large, rounded, ventricose Macoma. Specimens identified by
Dr. Dall.
Common in upper San Pedro series of San Pedro, and exceedingly so in the
Pleistocene of Los Cerritos, where they occur in beautifully preserved pains. A few
specimens found in the upper San Pedro series at Deadman Island and Crawfish
George's; and in the lower San Pedro series at Deadman Island. Found in the
Pliocene at Pacific Beach, and in the Pleistocene at Spanish Bight, San Diego.
Living. — Santa Barbara to San Diego (Cooper).
Pleistocene. — San Pedro (Cooper; Arnold): San Diego (Arnold).
Pliocene. — Santa Barbara (Cooper): San Fernando (Cooper; Arnold): Sau
Diego (Arnold).
Miocene. — Monterey; El Toro Ranch, Monterey County (Cooper).
Genus Macoma Leach.
Shell without lateral teeth, usually subtrigonal and with a marked posterior flexure; the
surface feebly sculptured concentrically, or smooth; the siphons naked.
Ty[)e, J\L tenera Leach.
ARNOLD— THE PALEONTOLOGY AND STKATIGEAPHY OF SAN PEDRO. 161
Subgenus Macoma s. s.
Shell subtrigonal, the periostracum conspicuous; usually colorless, or, if colored, without
color pattern; flexure well marked; the pallial sinus coalescent with the pallial line below, and often
discrepant in the two valves; inhabiting the cooler seas, and especially boreal waters.
104. Macoma calcarea Gmelin.
Plate XVI, Fig. 2.
Tellina calcarea, teste ovala, etc., Chem., Conch. Cab., Vol. VI, p. 140, Pi. XIII, fig. 136, 1782.
Tellina calcarea, Gmelin, Syst. Nat., Ed. VI, p. 3236, No. 38, 1792.
Macoma calcarea Chem. = Sanguiiiolaria californica Con. = Tellina pedroana Con. = Tellina
ienera Leach {fide Gabb, Pal. Cal., Vol. II, p. 124, 1869). Cooper, 7th Ann. Rept.
Gal. St. Min., 1888, p. 248.
Macoma calcarea GwEiAii. =^ Tellina lata Gmelin. = Tellina sudulosa Spenglkr. = Macoma tenera
Leach = Tellina proxima (Brown) Sby. = Telli>ia sordida Covrnovy . = Sanguino-
laria sordida Gld. {fide Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 5, 1900).
Shell of medium size, suboval, slightly convex, inequilateral, thin; anterior end shorter than
posterior, with fold running from apex to lower anterior extremity, which is biangular; anterior dorsal
margin straight; anterior end evenly rounded; beaks anterior to middle, small, inconspicuous;
surface sculptured by fine incremental lines; two cardinal teeth on left valve, anterior one bifid; pallial
sinus large.
Dimcnsio7is. — Long. 18.2 mm.; beak to anterior extremity 8.2 mm.; to posterior extremity
10 mm.; alt. 13.5 mm.; diam. 5.2 mm.
This species is distinguishable from M. yoldiformis by its more prominent fold
and much broader form; distinguished from others of this genus found in these
deposits by having the anterior (folded and angular) end shorter than the posterior
end. Specimens identified by Dr. Dall. Specimens of this species are labeled "J/.
expansa " in the State Museum Collection, at the University of California, at Berkeley.
Several specimens from the lower San Pedro series and Pliocene of Deadman
Island. Tiie specimen figured is from the lower San Pedro series at Deadman
Island, and is now in the collection of Delos Arnold.
Living. — Arctic and boreal seas, south on Atlantic Coast to Long Island
Sound, on Pacific Coast to Oregon and Northern Japan (Dall).
Pleistocene. — Scandinavia; Scotland; Greenland; Siberia; Alaska (Dall) : San
Pedro (Arnold).
Pliocene. — San Pedro (Arnold).
105. Macoma indentata Carpenter.
Plate XVI, Fig. 1.
Macoma indentata Cpr., Brit. Assn. Rept., 1863, p. 639. Cooper, 7th Ann. Rept. Cal. St. Min., 1888,
p. 248. Keep, West Coast Shells, p. 195, 1892. Williamson, Proc. U. S. Nat. Mus.,
Vol. XV, 1892, p. 185. Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 5, 1900, p. 1052.
Shell of medium size, rather narrow, suboval, compressed, thin; umbones slightly posterior
to center; anterior end long and evenly rounded; posterior dorsal line straight; ventral line near
( 21 ) January 9, 1903,
162 CALIFORNIA ACADEMY OF SCIENCES.
posterior end indented, the posterior extremity being much projected and sharply rounded; fold very
prominent; ligamental area short, scooped out.
Diinenstons. — Long. 50 mm.; alt. 32 mm.; diam. 14 mm.; umbo to anterior exremity
28 mm. ; to posterior extremity 22 mm.
Resembles M. nasitta and M. kcheiji, but is distinguishable by its smaller
shell, jwstei'ior umboiies, indentation in ventral margin, more prominent fold and
more prominently projected posterior extremity. Specimen identified by Dr. Dall.
Rare in the upper San Pedro series at Los Cerritos and San Pedro. Found
in the Pleistocene at Spanish Bight, San Diego. The specimen figured is from the
upper San Pedro series at Los Cerritos, and is now in the collection of Delos Arnold.
Living. — Monterey to San Diego (Cooper).
Pleistocene. — San Pedro (Arnold): San Diego (Cooper; Arnold).
Miocene. — El Toro Ranch, Monterey County; Griswold's, San Benito County
(Cooper).
106. Macoma inquinata Dcshaycs.
Plate XVI, Fu:. i.
Tellina inquinata Desh., Proc. Zoo). Soc, 1854, p. 357.
Macoma inquinata Desh., Carpenter, Brit. Assn. Rept., 1863, p. 689. Gabb, Pal. Cal., Vol. II,
p. 93, 1869. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 248. Keep, West Coast
Shells, p. 195, 1892. Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 5, 1900, p. 1053.
Shell of medium size, suboval, convex, thin, equivalve; umbones subcentral ; anterior end
dilated, rather prominently so in front of umbo of right valve; posterior end evenly arcuate from
umbo and acutely rounded at posterior end about half way between dorsal and ventral margins ;
ligament of medium length, not prominent; two small cardinal teeth in each valve; pallial sinus does
not reach anterior muscle-impression in the left valve.
Di?ne>isio7ts. — Long. 35 mm.; alt. 27 mm.; diam. 15 mm.; umbo to anterior extremity
16 mm.; to posterior extremity 19 mm.
Distinguishable by medium size, short, equally convex valves, very faint or
obsolete fold; evenly, acutely rounded, rather than truncated, posterior extremity,
and disconnection of pallial sinus and anterior muscle-impression. Specimen identi-
fied by Dr. Dall.
Not uncommon in the Pliocene at Deadman Island, the lower San Pedro
series at Deadman Island, and the upper San Pedro series at Deadmnn Island, San
Pedro, Los Cerritos, and Crawfish George's. Found also in the Pleistocene at
Twenty-sixtli Street, San Diego.
The specimen figured is from the upper San Pedro series at San Pedro, and
is now in the collection of Delos Arnold.
Living. — Alaska to San Diego (Cooper).
Pleistocene. — Monterey to San Diego (Cooper): San Pedro; San Diego
(Arnold).
Pliocene. — Twelve Mile House; San Fernando (Cooper).
AENOLD — THE PALEONTOLOGY AND STRATIGKAPHY OF SAN PEDRO. 163
107. Macoma nasuta Conrad.
Platk XVI, Fig. .S.
Tellina nasuta Con., Jour. Phil. Acad. Sci., Vol. VII, 1837, p. 258.
Macoma nasiUa Con. = y)/ tersa Gld., {fide Carpenter, Brit. Assn. Rept., 1863, p. 639). Gabb,
Pal. Cal., Vol. II, p. 93, 1869. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 248.
Keep, West Coast Shells, p. 194, fig. 165, 1892. Williamson, Proc. U. S. Nat.
Mus., Vol. XV, 1892, p. 185. Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 5, 1900,
P- 1053-
Shell of medium size, ovate, compressed, thin; anterior side dilated; posterior side cunei-
form, extremity truncated much above the line of the base; posterior dorsal margin straight to angle
where it joins line of truncation ; fold carinated on the right valve ; umbones slightly anterior to
center, slightly prominent; two prominent narrow cardinal teeth in each valve; no laterals; ligament
external, long, straight, narrow; pallial sinus large, expanding interiorly, that of the left valve joining
anterior muscle-impression at its lower posterior angle.
Dimensions.— "Long. 76 mm.; alt. 54 mm.; diam. 23 mm.; umbo to anterior end 31 mm.;
to posterior end 45 mm .
Distinguishable frora M. secta by smaller size, less convex valves, less alti-
tude, longer, straight posterior margin, and longer, less prominent ligaraental callus;
frora M.inquinata by larger, longer shell, less convex valves, less relative altitude,
straight dorsal margin with truncation posteriorly, and by less central umbones; from
M. yoldiformis by more cuneiform posterior extremity, long, straight posterior dorsal
margin, and by having the beaks anterior to center rather than posterior; frora
M. identata by beaks being more anterior, being broader, and by lacking the promi-
nent folds, indentation of ventral margin, and prominent projection of posterior
extremity; from M. kelseyi, which closely resembles it, by broader shell, and more
oblique truncation of posterior extremity. Specimens identified by Dr. Dall.
Rather common in the lower San Pedro series at Deadraan Island and San
Pedro, and the upper San Pedro series at Los Cerritos, Long Beach, Crawfish
George's, Deadman Island, and San Pedro. The upper San Pedro strata afford
larger specimens, as a rule, than those found in the lower San Pedro.
Found also in the Pliocene at Pacific Beach, and in the Pleistocene at Spanish
Bight and Pacific Beach, Sau Diego, and in the Pleistocene at Barlow's ranch, and
the old ditch, Ventura.
The specimen figured is frora the upper San Pedro series at San Pedro, and
is now in the collection of Delo^ Arnold.
Living. — Alaska to San Diego; Kamtschatka (Cooper).
Pleistocene. — Santa Barbara to San Diego (Cooper): San Pedro; San Diego;
Ventura (Arnold).
Pliocene. — Eagle Prairie and Danger Creek, Humboldt County; Santa Rosa;
San Fernando (Cooper): San Diego (Arnold).
Miocene. — Sunol, Alameda County; Foxin's, Santa Barbara County (Cooper).
164 CALIFORNIA ACADEMY OF SCIENCES.
io8. Macoma nasuta Conrad var. kelseyi Ball.
Mdcoma kelseyi Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 5, 1900, p. 1052, PI. XLIX, fig. 7.
Shell of medium size, elongate-ovate, compressed, thin; posterior extremity cuneiform,
obliquely truncated much above ventral margin; umbones nearly central; other characteristics
same as in M. 7iasuta.
Dimensions. — Long. 70 mm.; alt. 45 mm.; diam. 18 mm.; umbo to anterior end 31 mm.; to
posterior end 39 mm.
Distinguishable from other species by same characteristics that distinguish
M. nasuta; distinguished from M. naauta by narrower, Hatter shell, and more oblique
truncation of posterior end. Specimens identified by Dr. Dall.
Rare in the upper San Pedro series at San Pedro and Los Cerritos. Found
also in the Pleistocene at Twenty-sixth Street, San Diego.
Living. — San Diego and south (Dall).
Pleistocene. — San Pedro; San Diego (Arnold).
109. Macoma secta Conrad.
Plate XVI, Fig. 5.
Tellina secta Con., Jour. Phil. Acad. Sci., Vol. VII, 1837, p. 257. Hanley, Thes. Conch., p. 337,
PI. LXV, figs. 245, 248, 1847.
Macoma sec/a Con., Carpenter, Brit. Assn. Rept., 1863, p. 639. H. & A. Adams, Gen. Rec.
Moll., p. 401, 1858. = Telli?ia ligamettlina D¥.sn. {Jide Gabb, Pal. Cal., Vol. II, p. 73,
1869). Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 249. Keep, West Coast Shells,
p. 191, fig. 163, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 185.
Macoma {Rexithcerus') secta Con. = var. edulis (Nutt. mss.) Cpr. (fide Dall, Trans. Wagner Inst.
Sci., Vol. Ill, Part 5, 1900, p. 1053).
Shell large, suboval, slightly ventricose, rather thin; umbones subcentral, evenly rounded
anteriorly; posterior end truncated obliquely much above the base line; posterior dorsal margins
short, straight, sloping off quite steeply to angle where it meets line of truncation; fold prominent ;
surface sculptured bylines of growth; two cardinal teeth in each valve; ligament short, thick, inserted
on an elongated, oblique, rib-like callus; margin beneath the gape appearing as if cut or broken;
pallial sinus large, expanded within, not reaching to anterior muscle-impression.
Dimensions. — Long. 82 mm.; alt. 65 mm.; diam. 24 mm.
Distinguishable by large size, broad shell, subcentral umbones, equal convexity
of valves, and the prominent short ligamental callus. Resembles a Mactra somewhat
in outline. Specimens identified by Dr. Dall.
Found in the lower San Pedro series at Deadman Island and San Pedro; and
in the upper San Pedro series at Deadman Island, Los Cerritos, Crawfish George's,
San Pedro, and Long Beach. Found also in the Pleistocene at Spanish Right,
San Diego. The specimen figured is from the upper San Pedro series at San Pedro,
and is now in the collection of Delos Arnold.
Living. — Bodega Bay to San Diego; Japan (Cooper).
Pleistocene.— ^ani-A Barbara to San Diego (Cooper) : San Pedro; San Diego
(Arnold).
Pliocene. — Santa Barbara; San Fernando (Cooper).
ARNOLD — THE PALEONTOLOGY AND STRATIGEAPHY OF SAN PEDRO. 165
110. Macoma yoldiformis Carpenter.
Plate XVI, Fig. 6.
Macoma yoldiformis Cpr., Brit. Assn. Rept. 1863, p. 639. Cooper, 7th Ann. Rept. Cal. St. Min.,
1888, p. 249. Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 5, 1900, p. 1053.
Shell small, subelliptical, compressed, very thin and fragile; umbones slightly posterior to
center; anterior end evenly rounded, longer than posterior side, which is very faintly folded, biangular
and more cuneiform; surface smooth, except for very fine incremental lines; ligamental area scooped
out about one-half length of posterior end; teeth very small.
Dit?ie7tsions. — Long. 23 mm.; alt. 13.2 mm.; diam. 6 mm.; umbo to anterior extremity
13 mm.; to posterior extremity 10 mm.
This species is distinguishable from other members of the genus by its small
size, subelliptical form, very thin, smooth shell, posterior umbones and faint fold;
distinguishable from Tellina hodegensis by less cuneiform posterior end and smaller
size. Specimens identified by Dr. Dall.
Rare in the lower San Pedro series at Deadman Island. Rather common in
the Pleistocene at Spanish Bight, San Diego. The specimen figured is from this
locality, and is now in the collection of Delos Arnold.
Living. — Straits of Fuca to San Pedro (Cooper).
Pleistocene. — Santa Barbara (Cooper): San Pedro; San Diego (Arnold).
Family XXXI. SEMELIDiE.
Genus Semele Schumacher.
Shell rounded, subequilateral, beaks turned forwards; posterior side slightly folded; hinge
teeth two in right valve and two in left; laterals elongated, distinct in the right valve; external
ligament short, cartilage internal, long, oblique; pallial sinus deep, rounded.
Type, Tellina reticulata Spengler.
III. Semele decisa Conrad.
Amphidesma decisa CoN., Jour. Phil. Acad. Sci., Vol. VII, 1837, p. 234, PI. XIX, fig. 2.
5V?«f/if (/^ma Con., Carpenter, Proc. Zool. Soc, 1856, p. 213. Carpenter, Brit. Assn. Rept.,
1863, p. 640. Gabb, Pal. Cal., Vol. II, p. 94, 1869. Cooper, 7th Ann. Rept. Cal. St.
Min., 1888, p. 264. Keep, West Coast Shells, p. 190, 1892. Williamson, Proc.
U. S. Nat. Mus., Vol. XV, 1892, p. 186. Dall, Trans. Wagner Inst. Sci., Vol. Ill,
Part 5, 1900, p. 995.
Shell rounded, subequilateral, thick; beaks elevated, turned forward; posterior side shorter
than the anterior, direct, biangulated; fold distinct; anterior end evenly rounded; anterior dorsal
margin slightly depressed; surface with numerous, thick, concentric, rugose, slightly prominent
ribs; cartilage-process oblique; cardinal teeth obsolete; lateral teeth distinct; pallial sinus wide
and shallow.
Dimensio7is. — Long. 8.5 mm.; alt. 78 mm.; diam. 34 mm.
The specimen described is a large one. These shells are often found in
pairs in these deposits. . Specimens identified by Dr. Dall.
166 CALIFORNIA ACADEMY OF SCIENCES.
Rare in the lower San Pedro series at San Pedro; common in the upper San
Pedro series at Los Cerritos, but rarer in the same horizon at Deadraan Islam! and
San Pedro. Found also in the Pleistocene at Twenty-sixth Street, San Diego.
Living. — Santa Barbara to San Diego (Cooper).
Pleistocene. — San Pedro (Cooper; Arnold): San Diego (Arnold).
112. Semele pulchra Sovterby.
Plate XV, Fics. 1 and la.
Amphidesma pulchra Sv.Y . y Conch., Vol. Ill, No. 2, fig. 2.
Semele pukhra Sby., Carpenter, Brit. Assn. Rept., 1863, p. 640. Gabb, Pal. Cal., Vol. II, p. 94,
1S69. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 264. Keep, West Coast Shells,
p. 190, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 186. Dall,
Trans. Wagner Inst. Sci., Vol. Ill, Part 5, 1900, p. 995.
Shell small, oval, thin ; beaks turned forward ; posterior sides shorter than the anterior,
slightly biangular; fold not very distinct ; anterior dorsal margin slightly convex ; anterior end evenly
rounded ; surface sculptured with numerous fine, sharp concentric ridges, and fine radiating
striations; interior as in 6". decisa except more delicate, and cardinal tooth in each valve prominent.
Dimensions . — Long. 22 mm.; alt. 18.2 mm.; diam. 6 mm.
Distinguishable from 8. decisa by smaller, thinner shell, finer concentric
sculpture and radiating striations. Specimens of the species in the State Museum
Collection at the University of California, Berkeley, are labeled S. jiavescens Gld.
Specimens identified by Dr. Dall.
Rather rare in the upper San Pedro series at San Pedro and Los Cerritos.
Found also in the Pleistocene at Twenty-sixth Street, San Diego. The specimen
figured is from the upper San Pedro series at San Pedro, and is now in the collection
of Delos Arnold.
Living. — Santa Barbara to San Diego; Acapulco to South America (Cooper).
Pleistocene. — San Pedro (Cooper; Arnold): San Diego (Cooper; Arnold).
113. Semele pulchra So^rerby, montereyi, var. nov.
Plate XV, Figs. 4 and 4a.
Shell small, oval, ventricose, thin; beaks quite posterior to middle of shell; anterior dorsal
margin long, nearly straight; anterior extremity evenly curved; posterior end much shorter than
anterior, evenly rounded; fold obsolete; cartilage-process deep, oblique; one prominent cardinal
tooth in each valve; lateral teeth distinct; pallial sinus very large, rounded, expanded interiorly.
Dimensions. — Long. 23 mm ; alt. 17.5 mm.; diam. 11.5 mm.
Resembles 8. pulchra in size, but is much more oval, lacking the angular
appearance at the beak; the beaks are situated more anteriorly in var. montereyi and
the shell is much more ventricose. Easily differentiated from the typical 8. pulchra.
Pronounced a new variety of pulchra by Dr. Dall.
Rare in lower San Pedro series at Deadman Island.
ARNOLD — THE PALEONTOLOGY AND STRATIGEAPHY OF SAN PEDKO. 167
The specimen figured is not the type, which is larger, and is in the United
States National Mnseum. The specimen fignred came from the lower San Pedro
Series at Deadman Island, and is now in the collection of Delos Arnold.
Living. — Monterey (Dall).
Pleistocene. — San Pedro (Arnold).
Genus Cumingia Soiverbj.
Shell transversely oval, equivalve, rounded in front, subrostrated and slightly gaping behind;
small, thin, often irregular in form; hinge with a spoon-shaped cartilage-pit, and a small anterior
cardinal tooth in each valve; two elongated lateral teeth in the right valve, less developed in the left;
beaks small; surface concentrically ridged; pallial sinus very wide.
Type, Cianingia mutica Sowerby.
114. Cumingia calif ornica Conrad.
Cumingia californica Con., Jour. Phil. Acad. Sci., Vol. VII, 1837, p. 234, PI. XVII, fig. 12. Car-
penter, Brit. Assn. Rept., 1863, p'. 640. Gabb, Pal. Cal., Vol. II, 1869, p. 94.
Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 238. Keep, West Coast Shells, p. 196,
fig. 168, 1892. Williamson, Proc. U. S. Nat. Mas., Vol. XV, 1892, p. 186.
^C. similis A. Ad. {Jide Dall, Trans. Wagner Inst. Sci., Vol. Ill, part 5, 1900,
p. 100 1 ).
Shell of medium size, transversely oval, slightly venlricose, thin; umbones small, incon-
spicuous; anterior margin evenly rounded; posterior sloping from umbo at an angle of about 45
degrees, straight; posterior end somewhat obliquely truncated; surface sculptured by numerous,
about equidistant, sharp, narrow, concenlric ridges or frills; hinge with a triangular, spoon-shaped
cartilage-pit and a small anterior cardinal tooth in each valve; two elongated lateral teeth in right
valve, less developed in the left; pallial sinus very wide, expanded interiorly and deep.
Dimensions. — Long. 24.5 mm.; alt. 18 mm.; diam. 4.9 mm.
Resembles Macoma nasuta in general outline, but is easily distinguishable by
the sharp, concentric ridges. Specimens identified by Dr. Dall.
Found in the lower San Pedro series at Deadman Island and San Pedro, and
in the upper San Pedro series at Deadman Island, Crawfish George's, and San Pedro.
Living. — Monterey to San Diego; Mazatlan (Cooper): Japan (Stimson).
Pleistocene. — Santa Barbara; San Diego (Cooper): San Pedro (Arnold).
Family XXXII. PSAMMOBIID.E.
Genus Psammobia (Lamarck) Bowdich.
Subgenus Psammobia s. s.
Shell elongated, more or less pointed behind; compressed; somewhat rudely concentrically
sculptured; the posterior dorsal area frequently sculptured diversely from the disc; the pallial sinus
elongated and for the most part coalescent below with the pallial line.
Type, Psammohia feroehsis Grael.
168 CALIFORNIA ACADEMY OF SCIENCES.
115. Psammobia (Psammobia) edentula Gahb.
Silequaria edcntiila Gabb, Pal. Cal., Vol. II, p. 53, PI. XV, tig. 11, 1869. Cooper, 7th Ann.
Rept. Cal. St. Min., 1888, p. 264.
Psammobia edenhi/a Gabb, Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 5, 1900, p. 976.
Shell large, elongated, subelliptical, flattened, thin; beaks minute, posterior to middle;
surface marked by distinct lines of growth most prominent near the margin; cardinal margins
straight, sloping gently toward the ends; anterior end convexly and very obliquely subtruncate
above, produced and rounded below; posterior end broadly and regularly rounded, a little less
prominent below than above the middle; basal margin nearly straight; ligamental area long, pro-
jecting prominently beyond the cardinal line for nearly half the length of the anterior portion of the
shell; projected area with large groove on outside, flat on inside; two prominent cardinal teeth,
anterior less prominent and oblique; anterior muscle-impression large, subcircular; posterior smaller,
subelliptical; pallial sinus deep and wide.
Dimetisions. — Long. 135 mm.; alt. 6g mm.; diam. 13 mm.
This fine shell was originally described by Gabb from a specimen obtained in
the Pliocene of San Fernando. On account of the matrix in which his specimen
was imbedded, the hinge area and interior were only partly accessible, hence it was
deemed expedient to more fully describe the interior of the shell. Dr. Dall pro-
nounced the shell described above a member of the genus Psammobia. The cardinal
teeth, however, are rather large for one of this genus.
Rare in the upper San Pedro series of San Pedro; three good specimens
obtained.
Living. — ?
Pleistocene. — San Pedro (Arnold).
Pliocene. — San Fernando (Cooper).
Genus Sanguinolaria Lamarck.
Section Nuttallia Dall.
Shell large, suborbicular, inequivalve, more or less twisted, the right valve slightly flatter; tiie
posterior cardinal in the left valve obsolete; the pallial sinus narrow in front and somewhat detached
from the p.illial line.
Type, Sanguinolaria nultaUi Conrad.
116. Sanguinolaria (Nuttallia) nuttalli Conrad.
Sanguinolaria nuttalli Con., Jour. Pliil. Acad. Sci., Vol. VII, 1837, p. 230, PI. XVII, tig. 6.
Carpenter, Brit. Assn. Rept., 1863, p. 638. Keep, West Coast Shells, p. 19S,
fig. 170, 1892. Williamson, Proc. U. vS. Nat. Mus., Vol. XV, 1892, p. 185. Dall,
Trans. Wagner Inst. Sci., Vol. Ill, Part 5, 1900, p. 979.
Shell large, subovate, thin; right valve ventricose, left compressed; umbones small, distant
from anterior margin, slightly prominent, acute; surface smooth, e.xcept for fine incremental lines;
anterior dorsal margin sloping concavely; posterior end evenly rounded from beaks; anterior end
more sharply rounded and much more produced; ventral margin evenly curved; cardinal teeth
prominent, fragile; ligamental area prominently projecting beyond cardinal line.
Dimensions. — Long. 80 mm.; alt. 59 mm.; diam. 23 mm.
ARNOLD — THE PALEONTOLOCxY AND STRATIGRAPHY OF SAN PEDRO. 169
Distinguishable from Mncoma by the prominent ligaraental projection, hinge,
and less angular asj)ect. Sj^ecimens identified by Dr. Dall.
Rather rare in the upper San Pedro series at San Pedro and Los Cerritos.
• Living. — Santa Barbara to San Diego (Carpenter).
Pleistocene. — San Pedro (Arnold).
Genus Tagelus Gray.
Beaks median or subposterior; teeth two in each valve, simple, pedunculate; valves without
constriction or clavicle, straight; pallial sinus deep, reaching to or beyond the beaks; posterior
adductor scar rounded; pallial sinus with the ventral part partially coalescent with the pallial line.
Type, Solen gihhus Spengler.
117. Tagelus calif ornianus Conrad.
Soleciirliis calif orniajnis don., ]o\n. Phil. Acad. Sci., Vol. VII, 1837, p. 233, PI. XVIII, fig. 3.
Carpenter, Brit. Assn. Rept., 1863, p. 638. Cooper, 7th Ann. Rcpt. Cal. St.
Min., 1888, p. 265. Keep, West Coast Shells, p. 201, fig. 172, 1892.
Tagelus calif ornianus Coi^., Dall, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 184. Dall, Trans.
Wagner Inst. Sci., Vol. Ill, Part 5, 1900, p. 984.
Shell of medium size, oblong-oval, convex, thin; umbones about central; posterior dorsal
margin runs straight back from umbo parallel with base; anterior dorsal margin slightly depressed,
beginning a little below and in front of umbo, parallel with base; extremities evenly rounded; basal
margin slightly contracted in middle; ligamental area slightly projecting; cardinal teeth, two in each
valve, sharp and thin; pallial sinus long and wide, pointed.
Dimensio7is. — Long. 80 mm.; alt. 22 mm.; diam. 13 mm.
Specimens identified by Dr. Dall.
Rare in the lower San Pedro series at Deadman Island and San Pedro; com-
mon in the upper San Pedro series at Deadman Island, Los Cerritos, Crawfish
George's, San Pedro, and Long Beach. Also found in the Pleistocene at Twenty-
sixth Street, San Diego.
Living. — Santa Barbara to San Diego (Cooper).
Pleistocene. — Santa Barbara; San Pedro; San Diego (Cooper): San Pedro;
San Diego (Arnold).
Pliocene.^San Diego (Dall).
Family XXXIIl. DONACID^.
Genus Donax (Linne) Lamarck.
Shell elongate, smooth, with no posterior carination; ventral margins with obsolete serra-
tion; cardinal teeth two in each valve, the larger often bifid; laterals both in the left valve, the
anterior hardly distinguishable from the margin, of which it is a sort of modification.
Donax trunculus Linne is a characteristic species.
(22) January 10, laoa.
170 CALIFORNIA ACADEMY OF SCIENCES.
ii8. Donax californica Conrad.
Plate XIII, Fig. 9.
Donax californica Con., Jour. Phil. Acad. Sci., Vol. VII, 1837, p. 254, PI. XIX, fig. 21; (not of
Carpenter, Brit. Assn. Rept., 1863, p. 640.); (not of Cooper, 7th Ann. Rept. Cal.
St. Min., 1888, p. 238); (not of Keep, West Coast Shells, p. 192, fig. 164, 1892); (not
of Williamson, Proc. U. S. Nat. M us., Vol. XV, 1892, p. 186). = /?. navicula
Hanley (fide Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 5, 1900, p. 968).
Donax flexiiosus (not of Gould, Bost. Jour. Nat. Hist., Vol. VI, 1857, p. 394, PI. XV, fig. 8);
(not of Cpr., Brit. Assn. Rept., 1863, p. 640). ? Cooper, 7th Ann. Rept. Cal. St. Min.,
1888, p. 238. Keep, West Coast Shells, p. 192, 1892. ? Williamson, Proc. U. vS. Nat.
Mus., Vol. XV, 1892, p. 186.
Shell small, elongate-oval, rather pointed at both ends, thin; anterior end produced, quite
sharply rounded; posterior portion over one-half length of anterior, rounded end; surface obscurely
sculptured with fine radiating furrows; concentric, incremental sculpture sometimes visible; hinge
and teeth as in D. laevigata except more delicate; interior of margin finely crenulated.
Dimensions. — Long. 18 mm.; anterior portion 11 mm.; posterior 7 mm.; alt. 8 mm.;
diam. 6 mm.
Distinguishable from D. hmngata by smaller, narrower, thinner shell, more
elongated posterior portion and much less steeply sloping dorsal margin on this end.
This is the true D. californica Conrad, and not the californicas of Carpenter and
other later writers (see synonymy above). Specimens identified by Dr. Dall.
Rare in the lower San Pedro series at Deadmaii Island and San Pedro; and
in the upper San Pedro series at San Pedro. The specimen figured is from the lower
San Pedro series at Deadman Island, and is now in the collection of Delos Arnold.
Living. — Santa Barbara to San Diego (Cooper).
Pleistocene. — San Pedro (Arnold).
119. Donax laevigata De.shayes.
Plate XIII, Fig. 8.
Donax IcBvigata Deshayes, Proc. Zool. Soc, 1854, p. 352. Reeve, Conch. Icon., Vol. VIII,
PI. V, fig. 31. Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 5, 1900, p. 969.
Donax cali/ornicus (not. of Conrad, Jour. Phil. Acad. Sci., Vol. VII, 1837, p. 254, PI. XIX, fig. 21).
Carpenter, Brit. Assn. Rept., 1863, p. 640. Cooper, 7th Ann. Rept. Cal. St. Min.,
1888, p. 238. Keep, West Coast Shells, 192, fig. 164, 1892. Williamson, Proc.
U. S. Nat. Mas., Vol. XV, 1892, p. 186.
Donax obesus, Gld., Proc. Bost. Soc. Nat. Hist., Vol. IV, 1851, p. 90; Bost. Jour. Nat. Hist.,
Vol. VI, p. 394, PI. XV, fig. 9, 1857.
Shell rather small, trigonal, convex, wedge-like, closed; anterior portion produced, rounded,
upper margin straight; posterior portion very short and dorsal margin nearly straight, also angulated
at base; surface obscurely sculptured by fine radiating lines; incremental sculpture generally visible;
interior of margin strongly crenulated; hinge teeth two in each valve; laterals one anterior and one
posterior in each valve; pallial sinus deep.
Dimensions. — Long. 20.5 mm.; anterior portion 14 mm.; posterior 6.5 mm.; alt. 12 nnn.;
diam. 8 mm.
ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 171
This is the coraiuon Donax of the West Coast, and is easily recognized by its
triangular shape and the short, straight, posterior end. This species has been
erroneously called californicus by Carpenter and others since then, but a comparison
of one of these shells with Conrad's original figure and description of californica
readily shows the error. The true californica Conrad has a rather produced and
rounded posterior end, and is much narrower than kevigata. Specimens identified
by Dr. Ball.
Rare in the lower San Pedro series at San Pedro and Deadman Island;
common in the upper San Pedro series at San Pedro, Los Cerritos, Crawfish George's,
Long Beach, and Deadman Island. Found also in the Pleistocene at Barlow's ranch,
Ventura; and at Spanish Bight, Twenty-sixth Street, and Pacific Beach, San Diego.
The specimen figured is from the upper San Pedro series at San Pedro, and is now
in the collection of Delos Arnold.
Living. — Monterey?; San Luis Obispo to San Diego (Cooper).
Pleistocene. — San Pedro to San Diego (Cooper): San Pedro; San Diego;
Ventura (Arnold).
Superfamily SOLENACEA.
Family XXXIV. SOLENID^.
Genus Solen Linne.
Hinge with one cardinal in each valve; beaks nearly anterior; external surface polished;
valves usually straight.
Type, Solen marginatus Pulteney.
120. Solen rosaceus Carpenter.
Solen {stearins ? var.) rosaceus Cpr., Brit. Assn. Rept., 1S63, p. 638; Ann. & Mag. Nat. Hist.,
3rdSer., Vol. XV, 1865, p. 177.
KSb/f« ;wac«/j Cpr., Gabb, Pal. Cal., Vol. II, p. 88, 1869. Cooper, 7th Ann. Rept. Cal. St.
Min., 1888. p. 265. Keep, West Coast Shells, p. 202, 1892. Williamson, Proc. U. S.
Nat. Mus., Vol. XV, 1892, p. 184. Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 5,
1900, p. 952.
Shell of medium size, long, subcylindrical, slightly falcate, margins parallel, ends gaping;
beaks terminal; anterior extremity evenly rounded, projecting furthest a little below the middle;
posterior extremity very long, evenly rounded; hinge-teeth, one in each valve; ligament long, ex-
ternal; anterior muscle-impressions elongated; posterior oblong; sinus with squarish corners.
Dimensions. — Long. 55 mm.; alt. 10.5 mm.; diam. 6 mm.
This species much resembles S. sicarius but is much longer and narrower,
more cylindrical, and has a much more evenly rounded and less abruptly truncated
anterior extremity. Found also in the Plei.stocene at Spanish Bight, San Diego.
Living. — Santa Barbara south to Gulf of California (Dall).
Pleistocene. — Santa Barbara (Cooper): San Pedro (Arnold): San Diego
(Dall; Arnold).
172 CALlFOENIA ACADEMY OF SCIENCES.
Pliocene. — Santa Rosa; San Ramon, Kirker's Pass, Contra Costa County; San
Fernando; San Diego well (Cooper).
Miocene. — Toraales, Marin County; Martinez, Contra Costa County (Cooper).
121. Solen sicarius Gould.
Solen stearins Gv.T>. , Proc. Bost. Soc. Nat. Hist., Vol. Ill, 1850, p. 214; Wilkes' Expl. Exped.,
Vol. XII, p. 287, fig. 501, 1852. Carpenter, Brit. Assn. Rept., 1863, p. 638.
Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 265. Keep, West Coast Shells,
p. 202, fig. 173, 1892. Williamson, Proc. U. S. Nat. Mus. , Vol. XV, 1892, p. 184.
Dall, Trans. Wagner Inst. Sci. , Vol. Ill, Part 5, 1900, p. 952.
Shell of medium size, elongated, transversely oblong, cylindrical, slightly falcate; beaks
terminal; anterior extremity truncate obliquely at angle of about 30 degrees, somewhat everted, the
portion posterior to a line across from the beak to the base, concave; posterior extremity rounded;
dorsal edge rectilinear; ventral edge regularly arcuate; surface undulated by lines of growth; hinge
with single, erect, recurved, triangular tooth in each valve.
Diine7isions. — Long. 63 mm.; alt. i6mm. ; diam. 9'mm.
Distinguishable by its terminal beak and rather falcate outline. Specimens
identified by Dr. Dall.
Rather rare in the Pleistocene at Deadman Island and Timra's Point; com-
mon in the lower San Pedro series at Deadman Island and San Pedro; rare in
the upper San Pedro series at Los Cerritos, San Pedro, Crawfish George's, and
Deadman Island.
Living. — Straits of Fuca to San Pedro; Japan (Cooper).
Pleistocene. — San Pedro (Arnold).
Pliocene. — Twelve Mile Creek, San Mateo County; San Fernando (Cooper).
Miocene. — Walnut Creek, Contra Costa County (Cooper).
Genus Siliqua Megerle.
Shell smooth, oblong; epidermis polished; an umbonal rib extending across tiie interior of
the valve; pallial sinus short.
Type, Solen radius Linne.
122. Siliqua lucida Conrad.
bolecurtus lucida Con., Jour. Phil. Acad. Sci., Vol. VII, 1837, p. 232, PI. XVII, fig. 9; ^6". radiata
Linn, {^fide Conrad, Jour. Phil. Acad. Sci., 1849, p. 214). Dall, Solenidae, Proc-
U. S. Nat. Mus., Vol. XXII, igoo, p. 109.
Siliqua lucida Con., Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 5, 1900, p. 957.
Shell of medium size, oblong-oval, compressed, thin, fragile; umbo a little less than one-
fourth length from posterior end; interior raised callus sharp, narrow, perpendicular to dorsal margin;
other characteristics the same as in var. nuitalli.
Dimensions.— hong. 32 mm.; alt. 12 mm.; diam. 5 mm.; umbo to anterior end 25 mm.; to
posterior end 7 mm.
ARNOLD — THE PALEONTOLOGY ANt) STRATIGRAPHY OF SAN PEDRO. 173
This species is distinguishable from var. nuttalli by its small size, fragile shell,
more posterior umbo, and sharper, narrower, shorter, and more nearly perpendicular
interior callus. Dr. Dall in his paper on the Solenidte says that Carpenter (Brit.
Assn. Rept., 18G3, p. 634) and Gabb (1868) have confounded the young of S. nuttalli
with this species. A large series of S. lucida from the Pleistocene shows the above
mentioned differentiating characteristics to be constant. Specimens identified
by Dr. Dall.
Rather rare in the lower San Pedro series at Deadman Island and San Pedro;
and in the upper San Pedro series at San Pedro and Los Cerritos. Found also in the
Pleistocene at Twenty-sixth Street and Spanish Bight, San Diego.
Living. — Monterey to San Diego (Dall).
Pleistocene. — San Pedro; San Diego (Arnold).
123. Siliqua patula (Dixon) var. nuttalli Conrad.
Solecurtus 7mtlalli <Zo^., Jour. Phil. Acad. Sci., Vol. VII, 1837, page 232, PI. XVII, fig. 9.
Machccra patula, not of Dixon, Voy. Around the World, p. 335, fig. 2, 1789. Carpenter, Brit.
Assn. Rept., 1863, p. 638 (in part). Gabb, Pal. Cal, Vol. II, p. 89, 1869 (in part).
Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 248 (in part). ? Keep, West Coast
Shells, p. 201, fig. 171, 1892.
? Siliqna patula Dixon, Williamson, Proc. U. S. Nat. Mus. , Vol. XV, 1892, p. 185.
Siliqua nuttalli Q.o^., ■= S. californica CoN. {fide Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 5,
1900, p. 956).
Shell large, oblong-oval, compressed, thin, fragile; umbones a little over one-fourth length
from posterior end, minute; anterior end more acutely rounded than posterior; ligamental area
prominent, projecting beyond an equally long depression in the anterior dorsal margin; cardinal
teeth in right valve, four in the left; a strong, elevated callus extends over half way across the in-
terior of the shell from the umbo at nearly right angles with the dorsal margin.
Dimensions. — Long. loi mm.; alt. 39 mm.; diam. 14 mm.
Distinguishable from S. htcida by larger, heavier shell; distinguished from
I'agelus calif ornianus by the posterior position of the beaks, and by the more rounded
extremities. Specimens identified by Dr. Dall.
Rare; a nearly perfect pair from the upper San Pech-o series at San Pedro.
Found also in the Pleistocene at Spanish Bight, San Diego.
Limng. — Mouth of the Columbia River (Conrad).
Pleistocene. — San Pedro; San Diego (ArnoUl).
Pliocene. — ? Localities.
Miocene. — ? Localities.
174 CALIFORNIA ACADEMY OF SCIENCES.
Superfamily MACTRACEA.
Family XXXV. MACTRID.E.
Subfamily MAGTRIN.E.
Genus Mactra Linne.
Shell nearly equilateral; anterior hinge-tooth A-shaped, with sometimes a small laminar
tooth close to it; lateral tooth douisled in the right valve; ligament set off by a shelly lamina rising
between chondrophore and ligament; cardinals generally coalescent above; laterals smooth or finely
granular.
Type, Mactra stultorum Linne.
124. Mactra calif ornica Conrad.
Plate XIX, Fio. 2.
Mactra californica Con., Jour. Phil. Acad. Sci., Vol. VII, 1837, p. 240, PL XVIII, fig 12. Will-
iamson, Proc. U. S. Nat. Mus. , Vol. XV, 1892, p. 187. Dall, Trans. Wagner Inst.
Sci., Vol. Ill, Part 4, 1898, p. 876.
Standella calif ornica CoN., Carpenter, Brit. Assn. Rept., 1863, p. 640. Cooper, 7th Ann. Rept.
Cal. St. Min., 1888, p. 265. Keep, West Coast Shells, p. 190, 1892.
Shell of medium size, subtrigonal, subequilateral, compressed, thick; umbones subcentral,
turned anteriorly, margin only slightly arcuate; posterior side with a narrow, submarginal fold;
posterior extremity quite sharply rounded; anterior dorsal line slightly depressed in front of umbones;
anterior extremity evenly rounded; ventral margin evenly arcuate; surface sculptured with fine
concentric lines; cartilage pit triangular, deep, separated from posterior ligamental groove by a ridge;
cardinal teeth sharp, narrow, prominent; anterior ligamental groove long, narrow, with prominent
interior margin; pallial sinus rather deep, rounded, not coinciding with ventral line.
Dime7isions. — Long. 38 mm.; alt. 26 mm.; diam. 14 mm.; umbones to anterior extremity
17 mm.; to posterior extremity 21 mm.
The shell described was a small left valve, the only one so far obtained in the
San Pedro Pleistocene. This species closely resembles Spisula falcaia, bnt may be
distinguished from that species by its thicker shell, more obtusely rounded anterior
end, which gives it a less trigonal outline, and by the ridge which separates the
posterior ligamental groove from the cartilage pit. Distinguishable from other species
occurring in these beds by its almost central umbo, which turns slightly toward the
front. Several specimens of the young of this species show prominent concentric
undulations, reminding one somewhat of a small R(eta undulata.
Specimens identified by Dr. Dall. (Cooper makes M. californica and M.
lilanulata synonymous, and under this heading reports the species from several
localities in the Pleistocene, Pliocene and Miocene; but until his two forms are
differentiated it would be useless to give his localities.)
Rare in upper San Pedro series of San Pedro; one specimen found, which is
figured, and is now in the collection of Delos Arnold. Common in the Pleistocene
at Twenty-sixth Street, San Diego.
Living.- — San Francisco to San Diego (C^ar])enter).
Pleistocene.— ^a.u Pedro; San Diego (Arnold).
ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 175
125. Mactra exoleta Gray.
Plate XIX, Fig. 4.
Mactra exoleta Gray, = Lutraria venlricosa Gld. (yft/d? Carpenter, Proc. Zool. S(jc., 1856, p. 200).
Shell of medium size, decidedly Irigonal, ventricose, thin, fragile; umbones slightly anterior
to center, elevated, not touching, turned only slightly forward; anterior dorsal margin straight;
anterior e.xtremity evenly rounded near base; ventral margin evenly arcuate; posterior dorsal margin
arcuate, making an acute angle with the ventral margin; a sharp, prominent, angular ridge runs from
umbo to the posterior extremity; surface sculptured with fine, incremental lines, which are most
prominent posterior to ridge; cartilage-pit deep; hinge-teeth lamellar, long; ligamental groove very
deep and narrow.
Dimensions. — Long. 56 mm.; alt. 43 mm.; diam. 30 mm.; umbo to anterior e.xtremity
23 mm.; to posterior extremity 33 mm.
Distinguishable from others of genus by the sharply angular trigonal shape,
great convexity, elevatetl umbo, and sharp, submarginal posterior ridge. Specimen
identified by Dr. Dall.
Rare in upper San Pedro series of San Pedro; one nearly perfect right valve,
which is figured, and is now in the collection of Delos Arnold. Found also in the
Pleistocene at Spanish Bight and Pacific Beach, San Diego.
Living. — Coast of Mexico (Carpenter).
Pleistocene. — San Pedro; San Diego (Arnold).
126. Mactra hemphilli Dall.
Pl.\te XIX, Fu;. 3.
Mactra hefuphilli Dal-v, Nautilus, Vol. VII, 1894, p. 137, PI. V.
Shell large, subtrigonal, subequilateral, convex, rather thin; umbones slightly elevated,
subcentral, turned slightly forward; anterior portion hollowed in front of umbo, making the dorsal
margin slightly concave; anterior end evenly rounded; posterior dorsal margin evenly arcuate,
making a shorter turn into the ventral margin than does the anterior dorsal margin; posterior end
most produced near base; a prominent angular submarginal fold runs from the umbo to the posterior
extremity; hinge same as in M. calif arnica, except that the anterior ligamental groove is much shorter;
pallial sinus of medium size, very oblique.
Dimensions.— \^Q\-\^. 123 mm.; alt. 100 mm.; diam. 62 mm.; umbo to anterior extremity
50 mm.; to posterior extremity 73 inm.
This species is distinguishable from M. calif ornica by its greater altitude, more
concave anterior dorsal margin, shorter anterior ligamental groove, and oblique pallial
sinus; one of its unique characteristics being the oblique sinus. Specimen identified
by Dr. Dall.
Rare in upper San Pedro series of San Pedro; one specimen, which is figured,
and is now in the collection of Delos Arnold.
Pleistocene. — San Pedro (Arnold).
Subgenus Spisula Gray.
ate, set in a ca
lelly ridge.
Type, Mactra solida (Linn.) Gray.
Mactrae with ligament sagittate, set in a callous area close to the dorsal margin, and not set
off from the chondrophore by any shelly ridge.
176 CALIFORNIA ACADEMY OF SCIENCES.
127. Mactra (Spisula) catilliformis Conrad.
Plate XIX, Fig. 5.
Shell large, subtrigonal, slightly ventrico.se, rather thin; umbones slightly anterior to center,
marginal, not prominent; a long, rather narrow, hollowed submarginal space in front of umbo;
anterior dorsal margin straight; anterior extremity evenly rounded near middle of shell; posterior
margin sharp, nearly straight; posterior extremity more obtusely rounded than anterior; ventral
margin prominently and evenly arcuate; surface sculptured with fine incremental lines; posterior
submarginal fold very faint; cartilage-pit large, triangular, very prominent; cardinal teeth not
prominent; laterals narrow, short; anterior ligamental area not separated from cartilage-pit; pallial
sinus horizontal, rather broad and shallow.
Dimensions. — Long. 125 mm.; alt. 98 mm.; diam. 54 mm.; umbo to anterior extremity
50 mm.; to posterior extremity 75 mm.
Distinguishable by its large size, broad, almost oval outline, prominent
cartilage pit, long, depressed area in front of umbo, and nearly equally rounded ends.
Siiecimen identified by Dr. Dull.
Rather common in the upper San Pedro series at San Pedro, Los Cerritos,
Crawfish George's, and Deadraan Lsland. Found also in the Pliocene at Pacific
Beach, and in the Pleistocene at Pacific Beach, Spanish Bight and Twenty-sixth
Street, San Diego; and in the Pleistocene at Barlow's ranch, Ventura. The
specimen figured is from the upper San Pedro series at San Pedro, and is now in the
collection of Delos Arnold.
Living. — West Coast.
Pleistocene. — San Pedro; San Diego; Ventura (Arnold).
Pliocene. — San Diego (Arnold).
128. Mactra (Spisula) falcata Gould.
PL.ATK XIX, Fig. 1.
Mactra falcata Gld., Proc. Bost. Soc. Nat. Hist., Vol. Ill, 1S50, p. 216; Wilkes' Expl. Exped.,
Vol. XII, p. 393, fig. 506, 1852.
Standella falcata Gld., Carpenter, Brit. Assn. Rept. 1863, p. 640. Gabb, Pal. Cal., \'oI. II,
p. 92, 1869. ^5". nasuta Gld. {fide Cooper, 7th Ann. Rept. Cal. St. Min., 1888,
p. 266). Keep, West Coast Shells, p. 188, 1892.
Mactra planulata vat. falcata Gld., Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 187.
Shell of medium size, transversely ovate-triangular, convex, rather thin; umbones about
central, elevated; anterior dorsal margin nearly straight; anterior extremity rounded near base;
ventral margin subarcuate; posterior dorsal margin slightly arcuate, and in left valve lorming a
slight angle behind umbo; posterior extremity not quite as sharply rounded as anterior extremity;
submarginal posterior ridge rounded, not prominent; hinge as in catilliformis, except cartilage-pit
less prominent; pallial sinus rather long, with rounded extremity, horizontal; two broad, flat ridges
radiate from umbo on interior surface, forming a long, triangular depression between them.
Dimensions. — Long. 41 mm.; alt. 28 mm.; diam. 15 mm.
Distinguishable from other species by narrower, more acutely rounded ante-
rior end, and interior radiating ridges. Resembles J/, californicu, but is distinguishable
ARNOLD — THE PALEONTOLOGY AND STRATIOKAPHY OF SAN PEDRO. 177
by smaller pallial sinus, lack of ridge between cartilage-pit and anterior ligamental
groove, and by the interior radiating ridges and nairower anterior end. Specimens
identified by Dr. Dall.
Found in the lower San Pedro series at San Pedro and Deadman Island; and
in the upper San Pedro series at San Pedro, Deadman Island, Crawfish George's
and Los Cerritos. Also found in Pleistocene at Spanish Bight, San Diego. The
specimen figured is from the upper San Pedro series at San Pedro, and is now in the
collection of Delos Arnold.
Living. — Kodiak, Alaska, to San Diego (Cooper).
Pleistocene. — San Pedro (Arnold): San Diego (Cooper; Arnold).
Pliocene. — Eagle Prairie, Humboldt County; Kirker's Pass, Contra Costa
County (Cooper).
Miocene. — Martinez; Half Moon Bay, San Mateo County; Sunol, Alameda
County; Siebeck's, Santa Clara County; Griswold's, San Benito County; Foxiu's,
Santa Barbara County; Santiago, Los Angeles County (Cooper).
Subfamily PTEROPSIDIN.E.
Genus Labiosa {Schmidt) MMlcr.
Shell large, thin, inflated, broad and gaping behind, beaks adjacent; surface concentrically
striate; dorsal areas well defined; pallial sinus short, rounded, wide; ligament marginal, set off by a
prominent lamina of shell from the pit; a single obsolete and very short lateral in each valve before
and behind the pit; hinge-plate flattish behind, depressed and excavated in front.
Tyjie, Mactra anatina Spengler.
Subgenus Rceta Gray.
Shell acutely rostrate behind; dorsal areas obscure, the surface of the valves more or less
vermiculate; pallial sinus deep, narrow, pointed; ligament submerged, except at the anterior end,
set off by a shelly ridge which roofs the apex of the pit, and partially supports the posterior arm of
the cardinal tooth; left cardinal small; right cardinal with anus coalescent above; a single anterior
and posterior lateral in each valve.
Type, Lutraria canaliculata Say.
129. Labiosa (Raeta) undulata Gouhl.
Lutraria icndulafa Gld. , Proc. Bost. Soc. Nat. Hist., Vol. IV, 1851, p. 89; Bost. Jour. Nat. Hist.,
Vol. VI, 1853, p. 391. PI. XV, fig. 7.
Rata undulaia Gld., Carpenter, Brit. Assn. Rept., 1863, p. 640.
Lutra'ia transmontana CoN. {,fide Cooper, 7th Ann. Rept. Cal. St. Min., 188S, p. 247) [in part].
.Shell of medium size, ovate, ventricose, thin; beaks a little anterior to center; anterior
broadly rounded and tumid; posterior narrowed, compressed and acutely rounded, the dorsal margin
being a rectilinear slope, gaping; surface concentrically undulated; cardinal tooth strong; posterior
lateral tooth small.
( 23) 5Iarch4. 1903.
178 CALIFORNIA ACADEMY OF SCIENCES.
The above description was taken from Gould. A small fragment of a shell
showing the undulation of this species was found in the lower San Pedro series of
Deadraan Island. This fragment may have been of a young of Panopea generosa,
which is undulated in much the same way as Rada. Cooper likens this species to
Conrad's Lutraria tranamontana from the "Pliocene of Los Angeles County." One
perfect valve from the Pleistocene at Spanish Bight, San Diego. There is no doubt
as to the identity of the Spanish Bight specimen.
Living. — San Pedro to Lower California (Carpenter).
Pleistocene. — San Pedro? (Arnold): San Diego (Arnold).
Subfamily LUTRARIIN.K
Genus Tresus Gray.
Shell large, inequilateral, thin, inflated; siphonal gape very large, pedal gape narrow;
ligament minutely sagittate, separated by a shelly lamina from the pit, which lamina is often recurved
and patulous; left cardinal high, compressed; laterals small but distinct in both valves; right
cardinal feeble.
Type, 2Vesus nuttalli Conrad.
130. Tresus nuttalli Conrad.
Lutraria( Cryptodon) nuttalli Con.,] oxar. Phil. Acad. Nat. Sci., Vol. VII, 1837, p. 225, PI. XVIII, fig i.
Schizothwriis nuttalli Con., Pac. R. R. Rep., Vol. V, p. 234, PI. IV, fig. 33, 1853. Cpr., Brit.
Assn. Rept., 1863, p. 637, = Lutraria maxima Midd., = Madra maxit/ia (MiDV.)
RvE., = Lutraria capax Gld., = Tresus maximus (MiDD.) H. & A. Adams {Jide
Gabb, Pal. Cal., Vol. II, p. 91, 1869). Tryon, Syst. Conch., Vol. Ill, p. 161, PI. CX,
fig. 21, 1884. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 264. Keep, West
Coast vShells, p. 205, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 183.
Tresus nuttalli Qoh., Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 4, 1898, p. 885.
Shell large, subelliptical, convex, equivalve, inequilateral, thin; umbones small, anterior to
center; anterior dorsal margin evenly arcuate, sloping to anterior extremity, which is furthest pro-
duced below the middle; posterior aperture truncated, gaping; surface sculptured by prominent lines
of growth; one small cardinal tooth in each valve; cartilage-pit large, deep, triangular, separated
from ligamental groove by ridge; pallial sinus very large, broad, reaching nearly to line peqsen-
dicular to beak.
Dimensions. — Long. 103 mm.; alt. 73 mm.; diam. 44 mm.; umbo to anterior extremity
35 mm.; to posterior extremity 68 mm.
Externally the young of this species resemble somewhat the young of
Saxidomus, but may be distinguished by the thinner, slightly gaping shell, and
prominent cartilage-pit. Specimens identified by Dr. Dall.
Common in the upper San Pedro series at San Pedro, Los Cerritos, Crawfish
George's, and Deadman Island. Found also in the Pleistocene at Spanish Bight,
San Diego.
Living. — Alaska to San Diego (Cooper): both sides of North Pacific (Dall).
ARNOLD — THE PALEONTOLOGY AND STEATIGRAPHY OF SAN PEDRO. 179
Pleistocene. — Santa Barbara to San Diego (Cooper): San Pedro; San Diego
(Arnold).
Pliocene. — Santa Barbara (Cooper).
Superfamily MYACEA.
Family XXXVI. MYAGIDyE.
Genus Platyodon Conrad.
Shell ventricose, with concentric, undulating strise, and a small groove from the apex to the
ventral margin; posterior side short, radiately striated; spoon-shaped cardinal process dilated and
bi-emarginate.
Type, Platyodon cancellatuf^ Conrad.
131. Platyodon cancellatus Conrad.
Mya ca7icellahis Con., Jour. Acad. Nat. Sci., Phil, Vol. VII, 1837, p. 236, PI. XVIII, fig. 2.
Platjodo7i cancellatus Coti., CpR., Brit. Assn. Rept,, 1863, p. 637. Tryon, Syst. Conch., Vol. Ill,
PI. CVI, fig. 28, 1884. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 260. Keep,
West Coast Shells, p. 208, fig. 177, 1892. Williamson, Proc. U. S. Nat. Mus.,
Vol. XV, 1892, p. 1S3. Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 4, 1898, p. 858.
Shell of medium size, subelliptical, ventricose, thin; surface sculptured by numerous fine,
concentric lamina; of growth, and anterior portion with numerous fine radiating stri:e, which are
obsolete on the anterior portion; a slight furrow extends from the beak to the base; umbo promi-
nent; anterior end truncated and gaping; posterior end rounded; cardinal tooth very erect, dilated,
bi-emarginate.
Dimensions.- — Long. 49 mm.; alt. 28 mm.; diam. 22.5 mm.
Although belonging to the Myacidce, this species has somewhat the shape of
a Pholas, but may be distinguished by its sculpture. Most of the specimens found
were in pairs, and in a fine state of preservation. Specimens identified by Dr. Dall.
Rather rare in the upper San Pedro series at Deadman Island, San Pedro,
Los Cerritos, and Crawfish George's.
Living. — Bolinas Bay to San Diego (Cooper).
Pleistocene. — ? Santa Cruz (Cooper): San Pedro (Arnold).
Genus Cryptomya Conrad.
Shell inequilateral, transverse, oblong, gaping behind; valves with concentric strioe; right
valve with a lamellar tooth; left valve with a broad fosset; ligament internal; pallial sinus absent
or obsolete.
Type, Cnjptomyn californica Conrfid.
180 CALIFORNIA- ACADEMY OF SCIENCES.
132. Cryptomya calif ornica Conrad.
Sphcenia californica Con., Journ. Phil. Acad. Nat. Sci., Vol. VII, 1837, p. 234, PI. X\'II, fig. it.
Cpr., Proc. Zool. Soc, 1856, p. 210.
Cryptomya californica CoN., Proc. Phil. Acad. Nat. Sci., 1849, p. 121. Cpr., Brit. Assn. Rept., 1863,
p. 637, =C. oralis Qos. {Jide Gabb, Pal. Cal. Vol. II, p. 90, 1869). Cooper, 7th
Ann. Rept. Cal. St. Min., 1888, p. 237. Keep, West Coast Shells, p. 205, 1892.
Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 183. Dall, Trans. Wagner
Inst. Sci., Vol. Ill, Part. 4, 1898, p. 859.
Shell rather small, subelliptical, convex, equivalve, subequilateral, thin; anterior e.\tremity
biangular, with faint fold running down from umbo to lower portion of this e.xtremity; posterior
e-xtremity evenly rounded, slightly more produced below middle; ventral margin slightly arcuate;
surface sculptured by numerous fine, concentric, incremental lines; right valve with prominent
lamellar tooth, in which is a shallow cartilage-pit or chondrophore; left valve with a broad fosset;
pallial sinus obsolete.
Dimensions. — Long. 26.5 mm.; alt. iS mm.; diam. 5 mm.
Distinguishable from young of Tresus nuttalli by the lamelhir elevated tootli
and obsolete sinus. Specimens identified by Dr. Dall.
Found in the lower San Pedro series at Deadman Island and San Pedro;
and in the upper San Pedro series at San Pedro, Deadman Island, Los Cerritos,
Crawfish George's, and Long Beach. Found also in the Pleistocene at Twenty-sixth
Street and Spanish Bight, San Diego; and at the old irrigating ditch and Barlow's
ranch, Ventura.
Living. — British Columbia to Lower California (Dall).
Pleistocene. — San Pedro (Arnold): San Diego well (Cooper): San Diego;
Ventura (Arnold),
Pliocene. — Santa Rosa; Twelve Mile House, San Mateo County; Soquel, Santa
Cruz County; San Fernando; San Diego well (Cooper).
Miocene. — Siebeck's, Santa Clara County; Griswold's, San Benito County;
Foxin's, Santa Barbara County (Cooper).
Family XXXVH. CORBULID.F.
Genus Corbula (Bruguiere) Lamarck.
Valves unequal, the right usually larger, both more or less rostrate; hinge with (in the right
valve) a single large tooth below the beak, with a deep resiliary pit behind it, and no lateral laminae;
the left valve without laterals, with a process upon which the resilium and ligament are inserted, in
front of a socket, into which the cardinal tooth of the right valve fits; beaks prominent; sculpture
variable, never strongly radial; pallial line with a small sinus or none; kuuile and escutcheon usually
absent; ligament chiefly internal.
Corhula galli"n Lam. is a characteristic species.
ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 181
133. Corbula luteola C(ir/)enter.
Plate XVII, Fig. 11.
Corbula luteola CpR., Brit. Assn. Rept., 1S63, p. 637. Cooper, 7th Ann. Rept. Cal. St. Min., 1888,
p. 236. Keep, West Coast Shells, p. 204, 1892. Williamson, Pioc. U. S. Nat.
Mus., Vol. XV, 1892, p. 183. Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part IV,
1898, p. 856.
Shell small, subelliptical, gibbose, thick; beaks, subcentral, small, inconspicuous; anterior
extremity evenly rounded; posterior dorsal margin slightly arcuate, sloping down nearly to base,
where it turns abruptly, forming an angular extremity; ventral margin arcuate; a sharp sub-
marginal ridge extends from beak to lower portion of posterior extremity; surface sculptured with
fine, but distinct, concentric ridges; right valve with one prominent cardinal tooth in front of
cartilage-pit; left valve smaller, with a projecting cartilage process; pallial sinus slight; pedal scar
distinct from adductor impressions.
Dimensions. — Long. S mm.; alt. 5.5 mm.; diam. 3.5 mm.
This species is distinguishable by its peculiar shape, the sharp posterior, sub-
marginal ridge, and the delicate sculpture. Specimens ideutih'ed by Dr. Dall.
Found in the Pliocene at Deadman Island; in the lower San Pedro series
at Deadman Islaud and San Pedro; aud in the upper San Pedro series at San Pedro
and Los Cerritos. Also found in the Pleistocene at Twenty-sixth Street, San Diego.
The specimen figured is from the lower San Pedro series at Deadman Island,
and is now in the collection of Delos Arnold.
Living. — San Pedro to San Diego (Cooper).
Pleistocene. — San Pedro (Arnold): San Diego (Cooper; Arnold).
Pliocene. — San Pedro (Arnold).
Genus Neaera Gray.
Shell globular, attenuated, and gaping posteriorly; right valve a little the smallest: umbone
strengthened internally by a rib on the posterior side; cartilage- process spatulate, in each valve, with
an obsolete tooth in front, and a posterior lateral tooth; pallial sinus very shallow.
Necera ornatissima Irb. is a characteristic species.
134. Neaera pectinata Carpenter.
Plate XVIII, Fig. 11.
Neesra pectinata Cpr., Brit. Assn. Rept., p. 637, 1863.
Shell small, globular, attenuated and gaping behind, thin; umbones anterior; dorsal line
straight; anterior extremity evenly rounded; posterior extremity drawn out to a very long, narrow,
truncated beak; ventral margin greatly arcuate; surface sculptured by twelve prominent, sharp,
radiating ridges; posterior elongation smooth; cartilage-process spatulate, with an obsolete tooth
in front.
Dimensions. — Long. 6.5 mm.; alt. 3.4 mm.; diam. 2.3 mm.; umbo to anterior extremity
2.5 mm.; to posterior extremity 4 mm.
This unique little shell is distinguishable by its prominent radiating sculpture
and wing-like posterior projection. Specimen identified by Dr. Dall.
182 CALIFORNIA ACADEMY OF SCIENCES.
One nearly perfect right valve from the lower San Pedro series at Deadman
Island was obtained by Mrs. Oldroyd, is figured in this paper, and is now in the
collection of Mrs. Oldroyd. Later another valve was found at the same locality by
Delos Arnold.
Living. — Puget Sound to Santa Barbara, 40 to 60 fathoms (Carpenter).
Pleistocene. — San Pedro (Oldroyd; Arnold).
Family XXXVIII. SAXICAVID.E.
Genus Panopea Memird.
Shell equivalve, thick, oblong, gaping at each end; ligament external, on prominent ridges;
one prominent tooth in each valve; pallial sinus deep.
Mija glycymeris Born, is a characteristic species.
135. Panopea generosa Gould.
Panopea generosa Gld., Proc. Bost. Soc. Nat. Hist. Vol. Ill, 1S50, p. 215. Wilkes' E.xped.,
p. 385, PI. XXXIV, fig. 507, 1852.
Glycimeris generosa Gld., H. & A. Adams, Gen. Rec. Moll., p. 350, 1S53. Cpr., Brit. Assn.
Rept., 1863, p. 637. Gabb, Pal. Gal, Vol. II, p. 8g, 1S69. Cooper, 7th Ann. Rept.
Cal. St. Min., 1888, p. 241. Keep, West Coast Shells, p. 209, fig. 178, 1892.
Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 183. Dall, Wagner Inst.
Sci., Vol. Ill, Part 4, 1898, p. 830.
" Shell large, rather thin, nearly equilateral, the beaks slightly anterior, the dorsal and
ventral margins in the full grown shell parallel and nearly straight, the pedal margin evenly rounded,
the nymph narrow, and the attached edge of the ligament very short ; the pallial sinus wide
and shallow.
"Dimensions. — Long. 182 mm.; alt. no mm.; diameter 60 mm."
Dr. Dall gives the above description of a living, typical P. genernsn Gould
from Puget Sound. In the same paper (Tertiary Fauna of Florida, Trans. Wagner
Inst. Sci., Vol. Ill, Part 4, p. 831) he describes two new varieties of this same species
which he thinks have constant differences enough to warrant the separation. Variety
sollda Dall has a heavy, somewhat arcuate, shell, strong nymph, a ligamentary
attachment twice as long as in the typical form, and a deep pallial sinus. This and
the typical form are found from Puget Sound to San Diego. Variety glohosa Dall
has a short, thin, inflated shell with the beaks nearer the anterior end, which is ex-
panded and rounded in the pedal region; opposite margins not parallel; pallial sinus
small and wide. Found at head of Gulf of California.
Dall also classes together Mija abrupta Con. and Glt/ciineris estrellnna Con., of
the Miocene of California and Oregon, and differentiates them from P. generosa Gld.
under the name P. estrellana Con.
Two imperfect valves from the upper San Pedro series at Los Cerritos were
identified by Dr. Dall as typical P. generosa.
Rare in the Pliocene and lower San Pedro series at Deadman Island; and in
ARNOLD — THE PALEONTOLOGY AND STKATIGEAPHY OF SAN PEDRO. 183
the upper Sau Pedro series at Deadman Island, San Pedro, and Los Cerritos. Found
in the Pliocene at Packard's Hill, Santa Barbara.
Living. — Puget Sound to San Diego (Dall).
Pleistocene. — Santa Barbara to San Diego (Cooper): San Pedro (Arnold).
Pliocene. — Santa Barbara; San Fernando (Cooper): San Pedro; Santa Bar-
bara (Arnold).
Genus Panomya Gray.
Shell solid, large, irregular, with a single cardinal tooth under the beak in each valve; the
pallial line of unconnected rounded impressions.
Type, Panopea {Mtja) norvegica Spengler.
136. Panomya ampla JJaU.
Panomya ampla Dall, Trans. Wagner InsL Sci. , Vol. Ill, Part 4, 1S98, p. 833.
Panopea jiorvegica Midd. (pars.) Mai. Ross., Vol. Ill, p. 78, PI. XX, fig. 11, 1849 (not of Spengler)
(^fide Dall).
Shell large, irregularly subquadrate, ventricose, thick; beaks subcentral, incurved, small,
sharp, elevated; anterior extremity rounded, projected furthest above middle; posterior extremity
gaping, abruptly and irregularly truncated, with angular corners above and below; basal margin
nearly rectilinear; two large folds separate the shell into three parts; one fold extends to the lower
posterior angle from the umbo, and the other extends to the lower anterior angle from the umbo;
surface roughly sculptured by concentric lines and undulations; one small cardinal tooth in each
valve; cartilage-process rather short, projecting; pallial line of unconnected, rounded impressions.
Dimensions. — Long. 55 mm.; alt. 38 mm.; diam. 27 mm.
This species reminds one somewhat of a young Panopea generosa, but is
distinguishable from that species by the more central beaks, shorter and more
irregular shell, two prominent folds, and unconnected pallial line. Specimens
identified by Dr. Dall.
Rare in the Pliocene at Deadman Island; several perfect valves found.
Living. — North Pacific, Behring and Okhotsk Seas (Dall).
Pleistocene. — North Pacific, Behring and Okhotsk Seas (Dall).
Pliocene. — San Pedro (Arnold).
Superfamily ADESMACEA.
Family XXXIX. PHOLADID.E.
Subfamily PH0LAD1N.E.
Genus Zirphaea Leach.
Shell oval, cardinal margin scarcely reflected; no accessory valves, the beaks protected by
a membrane; usually a thin, fugacious epidermis; anteriorly greatly gaping.
Type, Pholas crispata Linne.
184 CALIFOUNIA ACADEMY OF SCIENCES.
137. Zirphaea gabbii Tryon.
Z/rfi/iiza gadi/i Tryon, Froc. Phil. Acad. Nat. Sci., 1866, p. 144, PI. I, fig. i. Gabb, Pal. Cal.,
Vol. II, pp. 52, 88, PI. XV, fig. 10, 1869. Cooper, 7th Ann. Rept. Cal. St. Min.,
1888, p. 270. Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 4, 1898, p. 818.
Zirpheca crispata (non Linn., Syst. Nat., Ed. X, p. 670, 1859) {fide Dall). Cpr., Brit. Assn.
Rept., 1863, p. 637. Keep, West Coast Shells, p. 210, fig. 179,1892. Williamson,
Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 182.
Shell of medium size, oblong, convex, thin; surface sculptured by concentric laminations,
which are much more elevated, and are provided with sharp, rasp-like teeth on the anterior half of
the shell; a slightly raised ridge, flanked by two shallow depressions, runs obliquely posteriorly from
the umbo, dividing the spiny sculptured area from the concentrically ridged area; valve reflexed from
the umbones forward, covering the umbones; each valve is provided with a delicate spoon-shaped
tooth or process, which joins the shell just beneath the umbo.
Dimensions. — Long. 72 mm.; alt. 35 mm.; diani. 30 mm.
This species, though closely allied to Z. crispata, is pronounced a distinct species
by Dr. Dall. Specimens identified by Dr. Dall.
Quite rare in the upper San Pedro series at Sau Pedro, Los Cerritos, Craw-
fish George's, and Deadman Island.
Pleistocene. — Santa Barbara (Cooper): San Pedro (Cooper; Arnold).
Miocene. — (?) Alameda County (Cooper).
Subfamily JOUAFNETIN.E.
Genus Pholadidea Goodall.
Shell with a double anterior accessory plate (protoplax), the other plate present or absent,
the valves prolonged behind into leathery or testaceous cups or a tube (siphonoplax) for the protec-
tion of the siphons.
Type, Pholadidea hscomhiana Goodall.
Subgenus Pholadidea s. s.
Shell with a double, rather small protoplax; the siphonoplax cup-like, the accessory plates
wanting; a single radial sulcus.
Type, Pholadidea hscomhiana Goodall.
m
Section Peiiiiella Valenciennes.
Like Pholadidea^ but with a small mesoplax, the two parts of the protoplax confluent.
Type, Pholas penita Conrad.
138. Pholadidea (Penitella) penita Conrad.
Pholas pcnila Con., Jour. Phil. Acad. Nat. Sci., Vol. VII, 1837, p. 237, PI. XVIII, fig. 7,
+ /'. concanierata Desh., 1840, -\-P. conradi Val., 1846 {fide Dall, Trans. Wagner
Inst. Sci., Vol. Ill, Part 4, 1898, p. 819).
Parapholas penita CoN. , Cpr., Proc, Zool. Soc, 1856, p. 210.
Pholadidea penita CoN., Cpr., Brit. Assn. Rept., 1863, p. 637. Cooper, 7th Ann. Rept. Cal. St.
Min., 1888, p. 259. Keep, West Coast Shells, p. 212, fig. 181, 1892. Williamson,
Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 182.
Penitella petiita Co-^., Tryon, Proc. Phil. Acad. Nat. Sci., Monog. Pliolad., 1861, p. 87.
Penitella spelcea CoN. {fide Gabb, Pal. Cal., Vol. II, p. 88, 1869).
AKNOLD — THE PALEONTOLOGY AND STHATIGBAPHY OF SAN PEDKO. 185
Shell of medium size, globose-oblong, equivalve, inequilateral, thin; beaks anterior, small,
covered by callous plate; transverse furrow from beak to middle of ventral margin; anterior portion
of shell with concentric, wavy, lamellae, which rise to sharp points on the crests of the undulations,
the points, taken as a whole, giving the impression of rugose, radiating, raised lines; posterior por-
tion of shell gaping, with surface concentrically sculptured; anterior gap large, closed in adult shell
by callous plate; with a small mesoplax, the two parts of the protoplax confluent.
Ditiiensiotis. — Long. 35 mm.; alt. 21 mm.; diam. 20 mm.
Rather common in the upper Sau Pedro series of San Pedro, Los Cerritos,
Crawfish George's, and Deadman Island.
Living. — Straits of Fuca to Santa Barbara (Cooper): San Pedro (Williamson).
Pleistocene. — Santa Barbara (Cooj)er) : Harris' ranch, Santa Barbara County
(Knecht): San Pedro (Arnold).
Class SCAPHOPODA.'
Order SOLENOCONCHIA.
Family XL. DENTALIIDiE.
Genus Dentalium Linne.
Shell tube-like, gradually tapering posteriorly; longitudinally ribbed; margin of the aperture
sharpened; posterior end with an internal, slightly projecting tube, which is provided with a dorso-
ventrally elongated opening, the outer layer having a very slight emargination dorsally and ventrally.
Dentalium elephantinum Linn, is a characteristic species.
139. Dentalium hexagonum Sowerhy.
Dentalium hexagonum Sbv., Thes. Conch., Vol. Ill, p. 103, fig. 10. Carpenter, Brit. Assn.
Rept., 1863, p. 648. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 238. Keep,
West Coast Shells, p. 114, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892,
p. 194.
Dcntaliicm neohcxagojium Sharp & Pilsbry, Tryon's Man. Conch., Vol. XVII, p. 19, PI. XI, figs.
74-86, 1898.
Shell small, curved, thin, tapering posteriorly; ape.x truncate; surface encircled by fine incre-
mental lines and generally by one or two irregular encircling grooves showing interruption in growth;
six prominent, equidistant, longitudinal ridges begin at posterior end and become obsolete near
aperture; cross-section near posterior end, hexagonal; aperture subcircular.
Dimensions. — ^Long. 33 mm.; diam. 3 mm.
Somewhat resembles a miniature elephant's tusk in shape.
Bather common in the lower San Pedro series at Deadman Island and San
Pedro; and in the upper San Pedro series at San Pedro, Deadman Island, Crawfish
George's, Los Cerritos, and Long Beach. Found in the Pleistocene at Barlow's
' The classification adoptod for this divisioa is that used by Dr. W. N. Dall in Part II of the "Contributions to the Tertiary Fauna
of Florida." The generic depcription is from Tiyon's "Structural and Systematic Conchology."
( 24 ) March i, 1903.
186 CALIFORNIA ACADEMY OF SCIENCES
ranch. Ventura; and in the Pliocene at Pacific Beach, and Kuss School, and in the
Pleistocene at Twenty-sixth Street, Spanish Bight, and Pacific Beach, San Diego.
Living.— Santfi Barbara to Mexico; East Indies; China (Cooper).
Pleistocene. — Santa Barbara to San Diego (Cooper) : San Pedro; San Diego;
Ventura (Arnold).
Pliocene. — San Diego well (Cooper): San Diego (Arnold).
140. Dentalium indianorum Carpenter.
Plate VIII, Fio. 4.
Dentalhim (J pretiosum Nutt., Sby., var.) hidiationan Cpr., Brit. Assn. Rept. , 1863, p. 648.
Dentalium indianorum Cpr., Cooper, 7th Ann. Rept. Cal. St. Min., 1S88, p. 238.
Dentalium preliosum var. indianorum Cpr., Tryon, Man. Conch., Vol. XVII, p. 45, PI. XIII,
figs. 4, 5, 6, 8, 1898.
Shell small, curved, tapering posteriorly, heavy; surface with fine incremental rings, and
striated posteriorly; cross-section and aperture circular.
Dimensions. — Long. 41 mm.; diam. 3 mm.
Some of the specimens are much more tapering than others. This species
is distinguishable from other members of the genus found in this locality by its
heavier shell, and by the striations near the posterior end. Specimens identified by
Dr. Dall.
Not uncommon in the lower San Pedro series of San Pedro and Deadman
Island; rare in the upper San Pedro series at Crawfish George's. The specimen
figured is from the lower San Pedro series at Deadman Island, and is now in the
collection of Delos Arnold.
Living. — Straits of Fuca to Santa Barbara (Cooper).
Pleistocene. — Santa Barbara (Cooper): San Pedro (Arnold).
141. Dentalium pseudohexagonum Dall.
Plate VIII, Fios. 12 and 12a.
Dentalium pseudohexagojium Dall, mss.
De7italiu7n 7ieohexai^onum Sharp & Pilsbry., Tryon, Man. Conch., Vol. XVII, p. 19, 1898, PI. XI,
figs. 74-86.
Shell small, curved, tapering posteriorly, rather heavy; surface ornamented with nine promi-
nent, rounded, elevated, longitudinal ridges, with concave interspaces; cross-section nine-sided;
aperture round.
Dimensions. — Long. 28 mm.; anterior diam. 2.8 mm.; posterior diam. 1 mm.
Distinguishable from the other members of the genus by the number of the
ridges. The specimen described was dark colored, whether natural or not is not
known. Specimen identified by Dr. Dall.
Rare in the lower San Pedro series at Deadman Island; one fine specimen
collected by Mrs. Oldroyd, and one by Delos Arnold; one or two specimens from
ARNOLD — THE PALEONTOLOGY AND STRATIGEAPHY OP SAN PEDRO. 187
the upper San Pedro series at San Pedro. Found also in the Pleistocene at Spanish
Bight, San Diego. The specimen figured is from the lower San Pedro series at
Deadman Island, and is now in the collection of Mrs. T. S. Oldroyd.
Living. — Locality unknown. Reported by Dall.
Pleistocene. — San Pedro (Oldroyd; Arnold): San Diego (Arnold).
142. Dentalium semipolitum Broderip <£■ Sowerhy.
Dentalium semipolitum Ekoh. 81 Sb\., CvK., Brit. Assn. Rept., 1S63, p. 648. Cooper, 7th Ann.
Rept. Cal. St. Min., 1888, p. 238.
Dentalium semistriatum var. semipolitum Brod. & Sby., Tryon, Man. Conch., Vol. XVII, p. 91,
PI. XVI, fig. 54, 1898.
Shell small, thin, tapering posteriorly, curved near posterior extremity; surface ornamented
by numerous fine longitudinal ridges; cross-section and aperture circular.
Dim.ensions. — Long. 10 mm.; diam. 1.4 mm.
Distinguishable from D. indianorum by striations along the whole length, and
smaller, thinner, and more tapering shell. Specimens identified by Dr. Dall.
Rare in upper San Pedro series at San Pedro, Deadman Island, and Crawfish
George's.
Living. — San Diego to Gulf of California (Cooper).
Pleistocene.- — San Pedro (Arnold).
Pliocene. — San Diego well (Dall).
Genus Cadulus Philippi.
Shell short, more or less inflated in the middle; apical orifice entire, circular, with annular
suboblique internal plica remote from the apex.
Cadulus subfusiformis Sars is a characteristic species.
143. Cadulus nitentior Carpenter.
Plate VIII, Fig. 15.
Cadidus 7iitentior Cpr., mss.
Cadulus fusiformis Phil., Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 231.
Cadulus fusi/ormis Sharp & Pilsbry, Dall, mss.
Shell small, dingy white or lustrous, tapering, falcate, tubular, thin; surface sculptured by
numerous incremental lines, and sometimes by slight constrictions; aperture circular.
Dimensions. — Long. 10 mm.; maximum diam. 1.2 mm.
Common in the lower San Pedro series at Deadman Island and San Pedro
bluffs. Found in the Pleistocene at Spanish Bight, San Diego. The specimen
figured is from the lower San Pedro series at Deadman Island, and is now in the
collection of Delos Arnold.
Living. — California Coast.
Pleistocene. — San Pedro; San Diego (Arnold).
Pliocene. — San Diego well (Cooper).
188 CALIFORNIA ACADEMY OF SCIENCES
Class gastropoda;
Order OPISTHOBRANCHIATA.
Family XLI. ACT^EONID^.
Genus Actaeon Montfori.
Sliell solid, ovate, with a conical, many-whorled spire, spirally grooved or punctate-striate;
aperture long, narrow, rounded in front; outer lip sharp; columella with a strong, tortuous fold.
I'ornatella faaciaia Laru. is a characteristic species.
144. Actason traskii Stearns.
Plate X, Fig. 6.
Ac/eeo7i iraskii SiRARtiS, Nautilus, Vol. XI, 1897, p. 14; Proc. U. S. Nat. Mus., Vol. XXI, 1899,
p. 297, text- fig.
Shell small, conical above, cylindrical, rather solid; sculpture consisting of numerous fine,
spiral, impressed lines, which become wider toward the base of the body-whorl, making the lower
portion of the shell Urate, and by sharp, close-set, incremental lines; these latter are subordinate to
the spiral sculpture; whorls six; suture distinct, narrowly channeled; aperture about two-thirds
length of the shell, acutely angular above, rounded and effuse below, finely lirate and glossy within,
with a thin glazing on the body-whorl; outer lip thin, simple; columella short and flexuous, with a
conspicuous fold curving around the same and thickening the edge of the lip, which is moderately
produced in the umbilical region.
Dimensions. — Long. 10 mm.; lat. 5.2 mm.; body-whorl 8.3 mm. aperture 7 mm.
Distinguishable from Eictaxis liundoadata by its larger size, more impressed
suture, more cylindrical body-whorl, more prominent and effuse anterior plication.
Specimens identified by Dr. Dall. Rare in upper San Pedro series of San Pedro.
Found in the Pleistocene at Spanish Bight, from which locality it was
originally described. The specimen figured is from the upper San Pedro series at
San Pedro, and is now in the collection of Delos Arnold.
? Living — San Diego (Stearns).
Pleistocene. — San Pedro (Arnold): San Diego (Stearns; Hamlin; Arnold).
Subgenus Rictaxis Dall.
I
Shell like Adaon, but with the columella projecting beyond the line of the anterior margin,
forming a small, tooth-like projection, or truncate obliquely.
Type, Tornatella pu7ictoc(£lata Cpr.
1 The classification of the Gastropoda is that used by DaU in Parta I and II of tlie " Contrlbutioas to the Tertiary Fauna of
Florida,'' and in Bulletin No. :i7. United States National Museum. The generic descriptions are for the most part from Tryon's " Struc-
tural and Systematic (^onchology."
ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 189
145. Acteeon (Rictaxis) punctoccelata Carpenter.
Plate IX, Fig. 6.
Toniaiel/a punctoccelata Cvv.., Brit. Assn. Rept., 1863, p. 646; Jour, de Conch., Vol. XII, 1865.
p. 139. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 267.
Rictaxis piincloccelata Cpr., Dall, Am. Jour. Conch., Vol. VII, 1872, p. 136, PI. XV, fig. 12.
Tryon, Syst. Conch., Vol. II, p. 356, PI. LXXXVII, fig. 28, 1883. Keep, West
Coast Shells, p. 125, fig. 115, 1892. Williamson, Proc. U. S. Nat. Mu.s., Vol. XV,
1892, p. 195. Tryon, Man. Conch., Vol. XV, p. 166, PI. LXIX, fig. 24, 1893.
Stearns, Proc. U. S. Nat. Mus., Vol. XXI, 1899, p. 298.
Shell small, elongate, elliptical, thin; spire small, conical; whorls three or four, convex;
sculpture consists of numerous fine, spiral impressed lines; body-whorl slightly ventricose; aperture
acutely angular above, rounded below; outer lip thin, simple; columella projecting beyond the line
of the anterior margin, or truncate obliquely; one sharp, columellar plait.
Dimensions. — Long. 6 mm.; lat. 2.7 mm.; body-whorl 5 mm.; aperture 3.5 mm.
Distinguishable from Actceon traskii by projecting columella, more ventricose
body-whorl, less effuse anterior lip, and smaller size.
Rare in the lower San Pedro series at Deadman Island and San Pedro,
and in the upper San Pedro series at San Pedro. Found also in the Pleistocene at
Spanish Bight, San Diego. The specimen figured is from the upper San Pedro
series at San Pedro, and is now in the collection of Delos Arnold.
Living. — Santa Cruz to San Diego (Cooper).
Pleistocene. — Santa Barbara to San Diego (Cooper): San Pedro (Arnold);
San Diego (Stearns; Arnold).
Family XLII. TORNATINIDiE.
Genus Tornatina A. Adams.
Shell cylindrical or fusiform, spire conspicuous, apex sinistral, suture channeled, columella
callous, single plaited.
Tornatina coarctata A. Adams is a characteristic species.
146. Tornatina cerealis Gould.
Plate X, Fio. 5.
Bulla (Tornatina) cerealis Gi^u., Bost. Jour. Nat. Hist, Vol. VI, 1853, p. 278, PI. XIV, fig. 9.
Tornatina cerealis Gi^u., Cpr., Brit. Assn. Rept., 1863, p. 647. Cooper, 7th Ann. Rept. Cal. St.
Min., 1888, p. 267. Tryon, Man. Conch., Vol. XV, p. 188, PI. L, figs. 39, 40, 1893.
Shell minute, solid, ovoid-fusiform, white; spire prominent, of three or four whorls rising by
regular grades, and mammillate at tip; aperture linear above, gradually widening forward: outer lip
salient at middle, and very gradually approaching the body of the whorl posteriorly, unites to it
before reaching the suture; columellar margin callous its whole length, with a strong fold at the base.
Dimensions. — Long. 4.5 mm.; lat. 2 mm.; spire 5 mm.; aperture 3.5 mm.
190 CALIFOENIA ACADEMY OF SCIENCES.
Distinguishable from T. culcitella by more angular whorls, maminillate apex,
more keeled upper edge of whorl, and smaller size. Specimens identified by
Dr. Dall.
Rather common in the upper and lower San Pedro series at San Pedro, and
in the lower San Pedro series at Deadman Island. Found also in the Pleistocene at
Spanish Bight, San Diego. The specimen figured is from the lower San Pedro
series at Deadman Island, and is now in the collection of Delos Arnold.
Living. — Monterey to San Diego (Cooper).
Pleistocene. — Santa Barbara; San Diego (Cooper): San Pedro; San Diego
(Arnold).
147. Tornatina culcitella Gould.
Plate X, Fig. 3.
Bulla (Akera) culcitella Gld., Bost. Jour. Nat. Hist., Vol. VI, 1853, p. 377, PI. XIV, fig 8;
Mex. & Cal. Shells, p. 14, PI. XIV, fig. 8, 1853.
Tornatina culcitella Gld., Cpr., Proc. Zool. See, 1856, p. 227. Cpr., Brit. Assn. Rept., 1863,
. p. 646. Gabb, Pal. Cal, Vol. II, p. 88, 1869. Cooper, 7th Ann. Rept. Cal. St.
Min., 1888, p. 268. Keep, West Coast Shells, p. 125, fig. 114, 1892. Williamson,
Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 195. Tryon, Man. Conch., Vol. XV, p. 189,
PI. L, fig. 38, 1893.
Shell small, thin, cylindrical, narrowed posteriorly; spire only slightly elevated; apex acute;
whorls four or five, suture appressed, distinct; aperture nearly as long as body-whorl, narrow
anteriorly, gradually widening anteriorly to near anterior end, where it quite suddenly retracts to
columella; columella with one plait.
Dimensions. — Long. 11 mm.; lat. 5 mm.; body-whorl 10 mm.; aperture 8.5 mm.
Some specimens attain the length of 23 mm.
Common in the upper and lower San Pedro series of San Pedro and vicinity.
Found also in the Pleistocene at bath-house, Santa Barbara; at Barlow's ranch,
Ventura, and at Twenty-sixth Street and Spanish Bight, San Diego. The specimen
figured is from the lower San Pedro series at Deadman Island, and is now in the col-
lection of Delos Arnold.
Living. — Monterey to San Diego (Cooper).
Pleistocene. — Santa Barbara (Cooper) : San Pedro; Santa Barbara; Ventura;
San Diego (Arnold).
148. Tornatina eximia Baird.
Plate X, Fio. 11.
Tornalina eximia Baird, Proc. Zool. Soc, 1863, p. 67. Cpr., Brit. Assn. Rept., 1863, p. 647.
Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 268. Tryon, Man. Conch., Vol. XV,
p. 189, 1893.
Shell resembles T. culcitella, but diflfers from that species in the following respects: Has a
whorl less narrowed anteriorly, a spire depressed nearly to rim of body-whorl, a longer and narrower
aperture, and a less prominent plait on the columella.
Dimensio7is. — Long. 12.4 mm.; lat. 5.5 mm.; body-whorl 12.2 mm.; aperture 11. 5 mm.
ARNOLD— THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 191
Specimen identified by Dr. Dall.
One specimen from the Pliocene at Deadman Island which is figured, and is
now in the collection of Delos Arnold.
Living. — Vancouver Island to San Diego (Cooper).
Pleistocene. — San Diego (Cooper).
Pliocene. — San Diego well (Cooper): San Pedro (Arnold).
149. Tornatina harpa Dall.
Tornatijia harpa Dall, Am. Jour. Conch., Vol. VII, 1872, p. 136, PI. XV, fig. 11. Keep, West
Coast Shells, p. 125, 1892.
Shell small, white, of four and a half whorls; tabulate and sharply carinate above, character-
ized by sharp grooves and raised lines, parallel with the lines of growth, which extend half over the
whorls and become obsolete anteriorly; apex mammillated, minute globular, prominent; suture
canaliculated; anterior portion of the last whorl smooth; last whorl slightly narrower above; aperture
long, narrow, effuse below, with a deep, narrow sinus at the suture; columellar plait obsolete in the
adult, rather prominent in the young shells; carina intersected by the grooves and slightly dentate.
Dimensiojis. — Long. 6 mm.; lat. 3 mm.
Easily distinguishable by the longitudinal sculpture on the upper half of the
last whorl.
Eare in the upper and lower San Pedro series at San Pedro. Found in upper
San Pedro series at Spanish Bight, San Diego.
Living. — Monterey (Dall): Catalina Island, 10 fathoms (Arnold, 1901).
Pleistocene. — San Pedro; San Diego (Arnold).
Genus Volvula A. Adams.
Shell subcylindrical, attenuated to a point posteriorly, to which the narrow aperture extends;
spire concealed; outer lip sharp; columella with an obsolete anterior plication.
Volvula acuminator Brug. is a characteristic species.
150. Volvula cylindrica Carpenter.
Platb IV. Fig. 2.
Volvula cylindrica Cpr., Brit. Assn. Rept., 1863, p. 647; Ann. & Mag. Nat. Hist., 3rd Ser., Vol. XV,
1865, p. 380. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 270. Williamson,
Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 195. Tryon, Man. Conch., Vol. XV,
1892, p. 239.
Shell small, cylindrical; flattened in middle and with margin almost parallel, swelling out
anteriorly; suddenly narrowed behind, running out into short, narrow, umbilicated point; aperture
length of shell; very narrow posteriorly, gradually broadening into subovate opening at anterior
end; surface smooth, except for faint lines of growth parallel to margin of shell.
Dimensions. — Long. 11 mm.; maximum diam. 4.5 mm.
Resembles Cylichna alba, but has an extended umbilical point. Dall (Trans.
Wagner Inst. Sci., Vol. Ill, Part 1, 1890, p. 16) mentions a ''Volvula cylindrica
192 CALIFORNIA ACADEMY OF SCIENCES.
Gabb" as occurring in tlie Miocene of San Domingo, and living on the Atlantic
Coast near Cape Hatteras. Whether or not this species is identical with the We;^t
Coast form the writer is unable to state.
Eare in the lower San Pedro series at Deadnian Island. Found in the
Pleistocene at Twenty-sixth Street, San Diego. The specimen figured is from the
lower San Pedro series at Deadman Island, and is now in the collection of Delos
Arnold.
Living. — Santa Barbara to San Diego (Cooper).
Pleistocene. — San Diego (Cooper): San Pedro; San Diego (Arnold).
Family XLIII. SCAPHANDRID^.
Genus Cylichna Loven.
Shell strong, cylindrical, smooth or punctate-striate; spire minute or truncated; aperture
narrow, rounded in front; columella callous, with one plait.
Cylichna arachis Quoy. is a characteristic species.
151. Cylichna alba Broivn.
) Plate X, Fio. IS.
Cy/ichia cyhfidracea (non LiNN.) Cpr., Brit. Assn. Rept., 1863, p. 647. Cooper, 7th Ann. Rept.
Cal. St. Min., 1888, p. 238.
Volvaria alba Brown, lUustr. Conch. G. B., p. 3, PI. XIX, figs. 43, 44.
Cylichna alba (BRO\wii)l^o\'^ii, Ofversight K. Vet.-Akad, Forh., 1846, p. 142. Tryon, Man. Conch.,
Vol. XV, p. 290, PI. LX, fig. 16, 1893.
Shell small, cylindrical, smooth; spire truncated; aperture narrow posteriorly for about two-
thirds length of shell, when the inner lip gradually retracts to tlie columella, forming a rounded
anterior end to the aperture; columella callous, with one plait.
Dimensions. — Long. 10.5 mm.; maximum diam. 4.25 mm.
Specimens identified by Dr. Dall.
Rare in the lower San Pedro series of Deadman Island, and upper San Pedro
series at San Pedro.
Found also in the Pleistocene at Spanish Bight, San Diego, and at Barlow's
ranch, Ventura. The specimen figured is from the lower San Pedro series at Dead-
man Island, and is now in the collection of Delos Arnold.
Living. — ^Monterey to San Diego (Cooper).
Pleistocene. — Santa Barbara; San Diego (Cooper): San Pedro; San Diego;
Ventura (Arnold).
Pliocene. — San Diego well (Cooper).
AKNOLD — THE PALEONTOLOGY AND STKATIGKAPHY OF SAN TEDKO. 193
Family XLIV. BULLION.
Genus Bulla Linne.
Shell oval-globular, smooth, spotted, marbled, or zoned; spire concave, umbilicated; aper-
ture as long as the shell; inner margin without columella; outer lip trenchant.
Bulla ampulla Linn. i.s a characteristic species.
152. Bulla punctulata ^4. Adams.
Bulla punciulata K. Ad., Thes. Conch., Vol. II, p. 604. Cpk., Proc. Zool. Soc. , 1863, p. 359.
Trvon, Man. Conch., Vol. XV, PI. 37, fig. 39; PI. XXXVI, figs. 29, 30, 1893.
Bulla punctata A. Ad., Thes. Conch., Vol. II, p. 577, PI. CXXIII, fig. 77; not of Schroeter.
Bulla adamsii Menke, Zeit f. MoL, p. 162, 1850. Cooper, 7th Ann. Rept. Cal. St. Min., i888, p. 230.
Shell of medium size, subglobular, thin; spire lacking; aperture full length of shell, broadly
ovate in front, narrowed posteriorly; outer lip thin, simple, gradually rounded near umbilicus; inner
lip and columella incrusted; umbilical pit at posterior end, deep, efifuse.
Dimeusions. — Long. 32 mm.; alt. 23 mm.; aperture 32 mm.
The shell described was an average specimen, some of the shells being larger
and some much smaller. Specimens identified by Dr. Dall.
This species is distinguishable from B. nehulosa by its longer, narrower, more
cylindrical body-whorl. B. punctulata is a southern shell, and is found but rarely
as far north as San Diego. B. nebulosn is the common form now living at San Pech-o.
Rather common in the upper San Pedro series of Deadman Island, Los
Cerritos, Crawfish George's, and San Pedro.
Living. — San Pedro to Panama (Cooper).
Pleistocene. — Sau Pedro (Cooper; Arnold).
Pliocene. — San Fernando (Cooper).
153. Bulla quoyi Gray.
Plate VIII, FlQ. S.
Bulla quoj'i Gray, Trav. in New Zealand, Diefi'enbach, Vol. I, p. 243, No. 113. Cpk., Brit. Assn.
Rept., 1863, p. 646.
Shell small, elliptical; aperture extending full length of shell; ovate in front, somewhat
narrowed behind; outer lip thin, angulated at posterior end; umbilicus at posterior end deep, not
very effuse; columella incrusted, the incrustation covering the anterior umbilical region.
DimeJisions. — Long. 8 mm.; alt. 5 mm.; aperture 8 mm.
The specimen described is a young shell. Identified as Bulla (juoiji by Dr.
Dall. Distinguishable from B. punctulata by angulation of outer lip near posterior
umbilicus, and the much sharper curve of the anterior lip.
Rare in upper San Pedro series of San Pedro; one young specimen found,
wliich is figured, and is now in the collection of Delos Arnold.
Living. — Santa Barbara to Lower California (Carpenter).
Pleistocene. — San Pedro (Arnold).
( 25 ) ilarcb 12, VJU3.
194 CALIFORNIA ACADEMY OF SCIENCES.
Genus Haminea Leach. .
Shell oval-globular, spiral ventricose, corneous, thin, covered by a slight, smooth epidermis;
spire involute.
Haminea hydatid Liiiii. i.s a chai'acteristic species.
154. Haminea virescens Sotcerbi/.
Platk VIII, Fio. 18.
Bu//a virescens Sby., Gen. Rec. Moll, No. XXXIX, fig. 2. A. Adams, Thes. Conch., Vol. II,
p. 579, PI. CXXIV, fig. 83, 1850. Cpr., Brit. Assn. Rept, 1S63, p. 646. = J7. cymbi-
formis Cpr. {fide Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part i, 1890, p. 18).
Keep, West Coast Shells p. 126, [892. Williamson, Proc. U. S. Nat. Mus.,
Vol. XV, 1892, p. 195. Tryon, Man. Conch., Vol. XV, p. 360, Pi. XL, fig. 5;
PI. XLIII, fig. 19, 1893.
Shell small, subglobular, thin; spire wanting; aperture full length of shell; posterior portion
of lip projects only slightly beyond apex; anterior part of aperture broadly ovate, tapering into a
canal at the posterior extremity; surface smooth and shell translucent.
Dimensions. — Long. 7 mm.; alt. 6 mm.; aperture 7 mm. x 4.5 mm.
One of the specimens shows tlie green color of the living sliells. Dr. Dall
says of this species: "The specimens (Caloosahatchie beds) have been com])ared
\vith typical specimens of H. virescenf^, and agree exactly. This is one of the cases
where, so far as known, a species formerly inhabiting both coasts of North America
lias become extinct since Pliocene times on one side of the continent while persist-
ing on the other. It is quite possible, however, that a more thorough exploration of
the Antillean region would show the s[)ecies still living there."
Rare in upper San Pedro series of San Pedro; two specimens found. The
specimen figured is from the upper San Pedro series at San Pedro, and is now in the
collection of Delos Arnold.
Living. — Santa Barbara to San Diego (Carpenter).
Pleiatocene. — San Pedro (Arnold).
Pliocene. — Caloosahatchie beds, Florida (Dall).
Order PULMONATA.
Suborder ST YLOMMATOPHORA.
Superfamily MONOTREMATA.
Family XLV. HELICIDiE.
Genus Helix Linne.
Subgenus Epiphragmophora Strobel.
.Shell umbilicate, fusco-calcareous; peristome e.xpanded, nearly circular; a solid calcareous
L-])ii)hram.
Helix cuyana Strobel is a characteristic species.
ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 195
155. Helix (Epiphragmophora) sp. indet.
Shell small, flattened, globosely conoidal; spire only slightly elevated; whorls three or four,
slightly convex; umbilicus narrow, deep; peristome expanded, nearly circular.
An imperfect Specimen of this genus was found in the lower San Pedro series
and sent to Dr. Dull, who pronounced it a member of the above genus.
Living. — (?)
Pleistocene. — San Pedro (Arnold).
Superfamily HYGROPHILA.
Family XLVI. LIMNyEID^.
Subfamily PLANORBIN^.
Genus Planorbis Guettard.
Shell discoidal, biconcave, the whorls visible on both sides; aperture small, rt)unded;
margin usually simple, sometimes expanded.
Planorhis corneus Linne is a characteristic species.
156. Planorbis tumidus Pfeifer.
Plate IX, Fig. KJ.
Pianordis iunn'dus Pi'eiff., Proc. Zool. Soc, 1S61, p. 232. Cpr., Brit. Assn. Re|)t., 1863, p. 55S.
Shell small, discoidal; spire, except last one and three-fourths whorls, slightly depre.ssed;
whorls four, breadth and height about equal; suture deeply impressed, the whorls sloping toward it;
base cup-shaped, exhibiting all of the whorls; aperture exhibiting a slightly oblique section of a
somewhat angular cylinder; lip embracing over half of body-whorl and joined by callus.
Dimeiisions. — Alt. 5 mm.; maximum diam. 12 mm.
Distinguishable from P. vermicular is by less sloping upper side of bod3'-whorl,
less depressed spire, and lip that is not expanded. Specimens identified by Dr. Dall.
Rare in upjier and lower San Pedro series of San Pedro; three specimens.
The specimen figured is from the upper San Pedro series at San Pedro, and is now
in the collection of Delos Arnold.
Living. — Guatemala (Carpenter).
Pleistocene. — San Pedro (Arnold).
157. Planorbis vermicularis Gould.
Plate IX, Pig. 14.
Pla7iorbis vermicularis Gld., Proc. Bost. Soc. Nat. Hist., Vol. II, 1847, p. 212; Wilkes' Expl.
Exped., Vol. XII, p. 112, fig. 131, 1852. Cpr., Brit. Assn. Rept., 1863, p. 675.
Shell small, dome-shaped; spire sunken into cup shaped depression below upper margin of
body-whorl; whorls four, breadth and height about equal, the last one deflected near the aperture,
196 CALIFORNIA ACADEMY OF SCIENCES.
rounded at periphery; suture very deep, the whorls sloping toward it; base cup-siiaped, exhibiting
all of the whorls; aperture exhibiting a very oblique section of a cylinder; slightly expanded, em-
bracing about one-half tiie height of the last whoil, and joined by callus.
Dimejisions. — Alt. 6 mm.; maximum diam. 11.5 mm.
Specimens itleiitified by Dr. Dall.
Rare in the upper and lower San Pedro series at San Pedro; three specimens.
Tlie specimen figured is from the upper San Pedro series at San Pedro, and is now
in tlie collection of Delos Arnold.
Livincj. — Interior of Oregon (Gould).
Pleistocene. — San Pedro (Arnold).
Family XLVII. PHYS1D.E.
Genus Physa Drap<irnaud.
Shell ovate, sinistrally spiral, thin, polished; aperture rounded in front.
Physa fontina lis Linn, is a chai'acteristic species.
158. Physa heterostropha Say.
P/ijsa //e/ffosOvp/m Say, Nichohon's Encyc]., PL LXIX, fig. 6. Cpr., Brit. Assn. Rept., 1863,
p. 674. Keep, West Coast Shells, p. 118, fig. 107, 1892.
Shell small, sinistral, shining, pellucid; whorls five ventricose; suture distinct; aperture
oval; outer lip thin; pillar lip strong and forms a conspicuous sinus where it joins the whorl above.
Dimensions. — Long. 12 mm.; lat. 7 mm.; body-whorl 10 mm.; aperture 8 mm.; defl.
95 degrees.
This fresh-water form, together with several other species having the same
habitat, was found in the lower San Pedro beds at San Pedro. There is no doubt as
to their occurrence in these marine de])Osits, into which they were probably washed
by some fresh-water stream.
Living. — North America.
Pleistocene. — San Pedro (Arnold).
Supcrfamily DITREMATA.
Family XLVIII. AURICULID^.
Subfamily MELAMPIN^.
Genus Melampus Montfort.
Shell oval-conoidal, or suboval, solid; spire rather short; aperture elongated, narrow;
columellar lip with several dentiform plications; columella plicate; outer lip sharp, interior with
revolving ridges.
Melampus luteus Quoy is a characteristic species.
ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 197
159. Melampus olivaceus Carpnnter.
A/('/amfi7is o/ivaccus Ctr., Mazatlan Cat., No. 235: Brit Assn. Rept., 1863, p. 647. Cooper, 7th
Ann. Rept. Cal. St. Min., 188S, p. 250. Keep, West Coast Shells, p. 124, fig. 113,
1892. Williamson, Proc. U. vS. Nat. Mus., Vol. XV, 1892, p. 196.
Shell small, thin, pyriform; spire solid, conical, barely elevated; whorls four or five, flat;
body-whorl comprises most of shell, slightly angulated above; suture appressed, wavy; aperture
long, narrow, rounded anteriorly; outer lip thin; inner lip incrusted, and with one prominent plica-
tion, and sometimes one or two more smaller ones; one prominent plication on columella; umbilicus
subperforate.
D/mensi'ons. — Long. 12 mm.; lat. 9 mm.; aperture 9.5 mm.
Somewhat resemble8 a small, thin, depressed Conus calif ornicus.
Found in all of the lower and upper San Pedro localities. Also found in the
Pleistocene at Twenty-sixth Street, San Diego.
Living. — Salinas River to Mazatlan (Cooper).
Pleistocene. — San Diego (Cooper): San Pedro; San Diego (Arnold).
Pliocene. — San Diego well (Dall).
Superfamily PETROPHILA.
Family XLIX. GADINIIDiE.
Genus Gadinia Gray.
Shell obliquely conical; muscular impression horseshoe-shaped, the right side shortest,
terminating at the siphonal groove.
Gadinia afra Gray is a characteristic species.
160. Gadinia reticulata SoiverJiij.
Mourctia rctinilaia Sby., Proc. Zoo). Soc, 1835, p. 6.
Gadinia reticulala Sby., H. & A. Adams, Gen. Rec. Moll., Vol. I, p. 463, 1853. Cpr., Brit. Assn.
Rept., 1863, p. 666. Dall, Am. Jour. Conch., Vol. VI, i87i,p. 11, PL II, figs, i to 9;
PI. IV, figs. I, 2 and 3. Keep, West Coast Shells, p. 98, fig. 83, 1892. Williamson,
Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 196.
Rowellia sp. Cpr., Brit. Assn. Rept., 1863, p. 651.
Gadinia (Rowellia) radiata Cooper, Gabb, Proc. Cal. Acad. Sci., Vol. Ill, 1865, p. 188. Cooper,
Geogr. Catal. Moll., p. 24, No. 460, 1867.
Rowellia radiqla Cooper, Am. Jour. Conch., Vol. VI, 1S71, p. 319.
Gadinia radiala Cooper, Dall, Am. Jour. Conch., Vol. VII, 1S72, p. 192.
Gadi?iia reticulata van radiata Cooper, Bull. No. 4, Cal. St. Min. Bureau, 1894, p. 26.
Shell conical; apex central, smooth, blunt; surface sculptured by numerous rounded,
radiating ridges, made somewhat nodose by concentric, elevated lines of growth; aperture slightly
ovate; inner surface smooth; lip smooth, effuse; color white.
Dime7isions. — Long. 15 mm.; lat. 14 mm.; alt. 5 mm.
Somewhat resembles Acmcea mitra, but is more depressed, has a le.ss acute
apex, and is sculptured radially. One specimen found in upper San Pedro series of
San Pedro.
198 CALIFORNIA ACADEMY OF SCIENCES.
Living. — Lower California (Carpenter) : West Coast (Keep) : Halfmoon Bay
(Arnold).
Pleidocene. — San Pedro (Arnold): San Nicolas Island (Bowers.
SuperoRler STREPTONEURA.
Order CTENOBRANCHIATA.
Superfamily TOXOGLOSSA.
Family L. TEREBRIDiE.
Genus Terebra Bruguiere.
Shell elongated, turriculated, narrow, solid; whorls numerous, rather flattened, with super-
ficially impressed sutures; aperture small, ovate, profoundly notched at base; columella oblique.
Terebra nebuloaa Sowerby is a characteristic species.
Section Acus (Humphrey) Gray.
i6i. Terebra (Acus) simplex Carpenter.
Myurella simplex Cpr., Brit. Assn. Rept., 1863, p. 657; Ann. & Mag. Nat. Hist., 3rd Sen,
Vol. XV, 1865, p. 395. Gabb, Pal. Cal., Vol. II, p. 78, 1869. Cooper, 7th Ann.
Rept. Cal. St. Min., 1888, p. 253. Keep, West Coast Shells, p. 56, fig, 40, 1892.
Terebra simplex Cpr., =T. variegata Gray (^fide Tryon, Man. Conch., Vol. VII, p. 14, 1885).
Terebra (Acus) simplex CpR., Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 207.
vShell small, turreted, slender; apex acute; whorls ten to eleven, flat; sculpture consists of
about fourteen faint, transverse ribs, each terminated on anterior end by a prominent node; a pseudo
suture separates the row of nodes from the main part of the whorl; incremental lines visible; suture
impressed, distinct; aperture subeljiptical; outer lip thin, slightly arcuate anteriorly; inner lip smooth;
plication on columella; sinus short.
Dimensions. — Long. 33 mm.; lat. 9 mm.; body-whorl 13 mm.; aperture 9 mm.; defl.
18 degrees.
Sculpture in this species is quite variable; some specimens have the row of
nodes prominently elevated, others show only a little constriction at upper third of
transverse ridge.
Common in upper, rare in lower San Pedro series of the San Pedro region.
Rare in the Pliocene of Deadman Island and Timm's Point. Found in the Pleis-
tocene at ]>arlow's ranch, Ventura, and at Twenty-sixth Street, Spanish Bight, and
Pacific Beach, San Diego.
Living. — Santa Barbara to San Diego (Cooper). '"'^d^v
Pleistocene. — Santa Barbara to San Diego (Cooper): San Pedro; San Diego;
Ventura (Arnold).
Pliocene. — San Diego well (Dall): San Pedro (Arnold).
ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 199
Family LI. CONID.E.
Geuus Conus Linne.
Shell thick, obconic, whorls enrolled upon themselves, the spire short, or not elevated,
smooth or tuberculated; aperture long, narrow, the margins parallel, truncated at the base; the outer
lip with a slight sutural sinus.
Conus nuirniorens Linn, is a characteristic species.
162. Conus californicus Hinds.
Conus californicus Hus., Proc. Zool. Soc, 1844; Voy. Sulphur, p. 7, PI. I, figs. 3, 4, 5, 1844.
= C. ravus Gld. {fide Cpr., Brit. Assn. Rept., 1863, p. 65S). Gabb, Pal. Cal.,
Vol. II, p. 78, 1869. Tryon, Man. Conch., Vol. VI, p 17, PI. IV, figs. 62, 63, 1884.
Cooper, 7th Ann. Rept. Cal. St. JNIin., 1888, p. 236. Keep, West Coast Shells,
p. 54, 1892.
Shell double-conical; spire compact, elevated; apex subacute; whorls seven or eight, flat,
smooth, except for incremental lines; suture irregular, appressed; body-whorl conical, subangular
anteriorly, spirally ornamented with fine lines, which are most prominent on lower part of whorl;
aperture long, narrow, slightly wider anteriorly; outer lip thin, bulging anteriorly; obsolete pos-
terior sinus.
DimeJisions. — Long. 34 mm.; lat. iS mm.; body-whorl 29 mm.; aperture 27.5 mm.; defl.
83 degrees.
The specimens from the Pleistocene are generally much worn, but some of
them retain the reddish brown coloration of the spiral lines and upper part of
the whorls.
Not uncommon in the Pliocene at Deadman Island and Timm's Point; in the
lower San Pedro series at Deadman Island and San Pedro; very common in the
upper San Pedro series at Deadman Island, Crawfish George's, Los Cerritos, San
Pedro, and Long Beach. Found also at Spanish Bight and Pacific Beach, San Diego.
Living. — Farallon Islands to San Diego; Lower California (Cooper).
Pleistocene. — Santa Barbara to San Diego (Cooper): San Pedro; San Diego
(Arnold).
Pliocene. — San Fernando (Cooper): San Pedro; Stanford University (Arnold).
Family Lll. PLEUROTOMID.E.
Genus Pleurotoma Lamarck.
vShell turriculated, fijsiform, terminated anteriorly by a straight, more or less long canal;
aperture oval; columellar lip smooth, straight or sinuous; outer lip somewhat sinuous, with a pos-
terior sinus.
Pleurotoma hahijlonia Lara, is a characteristic species.
200 CALIFORNIA ACADEMY OF SCIENCES.
163. Pleurotoma perversa Gahb.
Pleicrotoma perversa Gabb, Proc. Cal. Acad. Sci., Vol. Ill, 1865, p. 183; Pal. Cal., Vol. 11, pp. 6,
73, PI. I, fig. ID, 1869. Cooper, 7th Ann. Rept. Cal. St. Min., i888, p. 260.
Snrcula perversa, Gabb, Tryon, Man. Conch., Vol. VI, p. 239, PI. VI, fig. 79, 1884.
Shell small, sinistral, elongate, slender; whorls eight to eleven, convex; surface smooth
except lor fine incremental lines which are convexly angulated posteriorly a little above middle of
whorl; suture deeply impressed, distinct; aperture elongate-ovate; outer lip arcuate anteriorly; inner
lip incrusted; columella smooth; posterior sinus prominent; anterior sinus long, narrow.
Dimensions. — Long. 42 mm.; lat. 11.5 mm.; body-whorl 21 mm.; aperture, including canal,
16 mm.; defi. 18 degrees.
Distinguishable from other member.-? of thi.s family by being sinistral.
Common in the Pliocene and lower San Pedro series at Deadman Island; in
lower San Pedro series at San Pedro; and rare in the npper San Pedro series at
Deadman Island, San Pedro, and Los Cerritos. Common in upper San Pedro series
at Crawfish George's.
Living. — Vancouver Island to Cutalina Island (Coojser).
Pleistocene. — Santa Barbara to San Pedro (Coojier) : San Pedro (Arnold).
Pliocene. — San Pedro (Arnold).
Subgenus Borsonia Bdlardi.
Shell fusiform; with a plication upon the middle of the columt'll.i.
Pleurotoma j^yrenaica Roualt is a characteristic species.
164. Pleurotoma (Borsonia) bartschi, sp. nov.
PL.4TE V, Fig. 7; Plate IX, Fig. 1.
Shell small, fusiform, elongate; apex obtuse, mammilliform; whorls seven, angulated near
middle; body-whorl less angulated than those of spire; anterior portion of whorl ornamented with
about twelve oblique, transversely elongated nodes, which reach their greatest prominence on the
angle of the whorl; body-whorl sometimes smooth and sometimes nodose; posterior portion of whorl
flat and smooth except for incremental lines; incremental lines fine, oblique, and angulated convexly
posteriorly on upper portion of whorl; suture deeply appressed, distinct; aperture elongate-elliptical;
outer lip thin, arcuate anteriorly below posterior sinus; inner lip incrusted; columella nearly straight,
incrusted, with one sharp plication in middle of aperture; posterior sinus shallow; anterior sinus
prominent.
Dimensions. — Long. 19 mm.; lat. 7 mm.; body-whorl 11. 5 mm.; aperture, including canal,
8.5 mm.; defi. 28 degrees.
Distinguishable from B. dallii and B. hooveii by the prominent nodes on the
whorls. Looks very much like Drillin tnrosa, but is easily distinguishable by the
plication on columella and more angulated body-whorls. Pronounced a new species
by Dr. Dall. Specimens of Borsonia bartschi in the State Museum collection of
fossils at Berkeley are labeled "Drillia mutsta."
ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 201
Rare in the Pliocene and lower San Pedro series at Deadman Island. The spe-
cimen figured on Plate IX is the type, which is from the lower San Pedro series at
Deadraan Island, and is now in the United States National Museum; the specimen
figured on Plate V is a stumpy form, which might be called variety curta.
Pleistocene. — San Pedro (Arnold).
Pliocene. — San Pedro (Arnold).
165. Pleurotoma (Borsonia) dalli, sp.nov.
Plate VI, Fig. 2.
Shell small, fusiform; spire elevated; ape.x mammilliform; whorls eight, sharply angulated
a little anterior of middle; body-whorl less angulated than those of spire; posterior portion flat to
slightly concave, anterior portion slightly conve.x; first four whorls slightly nodose on angle; orna-
mentation consists of fine oblique, incremental lines which are convexly angulated posteriorly just
posterior to angle of whorl; suture deeply impressed, distinct; aperture elongate-elliptical; outer lip
thin, arcuate anteriorly; inner lip incrusted; columella slightly recurved, with one prominent plication
in middle of aperture; posterior sinus prominent; anterior sinus rather short.
Dime7isions. — Long. 23.5 mm.; lat. 9 mm.; body-whorl 13 mm.; aperture, including canal,
10 mm.; defl. 27 degrees.
Distinguishable by mammilliform apex, small deflection, sharply angulated,
smooth whorls, and plication on columella. Specimens pronounced new species by
Dr. Dall.
Rare in lower San Pedro series and Pliocene at Deadman Island. The speci-
men figured is tiie type, which is from the lower San Pedro series at Deadman
Island, and is now in the United States National Museum.
Pleistocene. — San Pedro (Arnold).
Pliocene. — San Pedro (Arnold).
166. Pleurotoma (Borsonia) hooveri, sp. nov.
Plate X, Fig. 1.
Shell small, fusiform; apex mammilliform; whorls five or six, angulated slightly anterior to
middle; body- whorl less angulated than those of spire; surface smooth, except for incremental lines,
which are oblique, and angulated convexly posteriorly a little above angle of whorl; suture deeply
impressed, distinct; aperture elliptical; outer lip thin, arcuate anteriorly below posterior sinus; inner
lip incrusted; columella incrusted, straight, with one prominent plication in middle of aperture; pos-
terior sinus shallow; anterior sinus short.
Dimensions. — Long. 13 mm.; lat. 6.5 mm.; body-whorl 8.2 mm.; aperture, including canal,
6.5 mm.; defl. 50 degrees.
Distinguishable from B. dallii by greatly depressed spire, fewer whorls and
lack of nodes on apical whorls. Pronounced a new species by Dr. Dall.
Rare in lower San Pedro series; two found at Deadman Island. The speci-
men figured is the type, which is from the lower San Pedro series at Deadman
Island, and is now in the United States National Museum.
Pleistocene. — San Pedro (Arnold).
( 26 ) March 12, \WJ.
202 CALIFORNIA ACADEMY OF SCIENCES.
Subgenus Leucosyrinx Dull.
167. Pleurotoma (Leucosyrinx) pedroana, sp. nov.
Plate IX, Fig. 4.
Shell small, elongated; ape.x subacute; whorls six, sharply angulated near anterior margin;
upper portion of whorls flat; ornamentation consists simply of incremental lines, which are angulated
convexly posteriorly a little posterior to the angle of the whorl; lower portion of body-whorl, and
sometimes the lower portion of the upper whorls, faintly spirally ribbed; deep sutural canal; aperture
ovate; outer lip thin, bulging anteriorly; inner lip smooth; posterior rims shallow and wide; canal
long, narrow; columella slightly recurved.
Dimensio7is. — Long. 17 mm.; lat. 6 mm.; body-whorl 10 mm.; aperture 7 mm.; defl.
22 degrees.
Distinguishable by the deep, canal-like suture and the prominence of the
angulation on the lower part of the whorls. Specimens identified by Dr. Dall as
being new.
Rare in lower San Pedro series at Deadman Island; three specimens found.
The specimen figured is the type, which is from the lower San Pedro series at Dead-
man Island, and is now in the United States National Museum.
Pleistocene. — San Pedro (Arnold).
Subgenus Genota Adams.
Section Dolichotoma Bellardi.
Shell mitrieform; whorls finely cancellated; aperture elongated, canal short; sinus profound.
Pleurotoma mitrceformis Kiener is a characteristic species.
168. • Pleurotoma (Dolichotoma) carpenteriana Gahb.
Pkurotoina (Siircida) carpenteriana Gabb, Proc. Cal. Acad, Sci., Vol. Ill, 1865, p. 183; Pal. Cal.,
Vol. II, pp. 5, 72, PI. I, fig. 8, 1869.
Siircula carpenieria7ia Gabb, Tryon, Man. Conch., Vol. VI, p. 239, PI. VII, fig. 3, 1884. Cooper,
7th Ann. Rept. Cal. St. Min., 1888, p. 266. Keep, West Coast Shells, p. 57,
fig. 41, 1892.
Genota carpenteriana Gabb, Dall, Proc. U. S. Nat. Mus., Vol. XII, 1889, p. 303.
Pleurotoma (Dolichotoma) carpejiteriajia Cpr., Williamson, Proc. U. S. Nat. Mus., Vol. XV,
1892, p. 207.
Shell large, fusiform; spire elevated and about as long as the aperture; whorls eight, sub-
flattened on the sides, slightly concave near suture, and very slightly convex anteriorly; surface
ornamented with fine spiral ridges, which alternate in size on lower part of body-whorl; suture im-
pressed; aperture narrow, widest in middle; outer lip thin, arcuate anteriorly below the wide, shallow
sinus; inner lip smooth, incrusted; canal broad and short.
Dimensions. — Long. 88 mm.; lat. 33 mm.; body-whorl 66 mm.; aj^erture, including canal,
50 mm.; defl. 38 degrees.
The specimen described is an exceediugly fine specimen, a little above the
average in size. Mrs. Oklroyd has over a dozen fine specimens of the living shells
of this species, which have been hauled up in the fishermen's nets at San Pedro.
ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 203
Not uncommon in the upper San Pedro series at San Pedro, Deadman Island,
and Crawfish George's. Found also in the Pleistocene at Pacific Beach, San Diego,
and at the old irrigating ditch, Ventura.
Living. — Monterey to San Diego (Cooper): Cerros Island (Dall).
Pleistocene. — Santa Barbara; San Pedro (Cooper): San Pedro; San Diego;
Ventura (Arnold).
Pliocene. — Santa Rosa; San Fernando (Cooper): San Diego well (Dall).
169. Pleurotoma (Dolichotoma) cooperi, sp. nov.
Plate VII, Fig. 3.
Shell large, fusiform; spire elevated, same length as aperture; whorls seven, prominently
angulated near middle; upper portion decidedly concave, lower portion slightly convex; first five
whorls slightly nodose on angle, rest of whorls smooth on angle, except for roughness caused by in-
cremental lines; surface ornamented with revolving spiral ridges, most prominent on the lower portion
of whorls, and with prominent incremental lines, which, following the outline of the lip, are convexly
angulated posteriorly on the upper portion of the whorl and concavely angulated on the lower
portion; on the upper whorls the nearly equal prominence of the two systems of sculpture give the
shell a cancellated appearance; aperture long, narrow, with sides nearly parallel; outer lip thin,
arcuate anteriorly below sinus; inner lip smooth, incrusted; posterior sinus shallow, broad; canal
short, nearly as wide as aperture.
Dimensions. — Long. 65 mm.; lat. 24 mm. ; body- whorl 42.5 mm.; aperture, including canal,
33 mm.; defl. 39 degrees.
Distinguishable by the decided convexity of the upper portion of the whorl,
smooth angle and cancellated appearance of upper whoi'ls.
Rare in upper San Pedro series of San Pedro; one specimen found. The
specimen figured is the type, which is from the upper San Pedro series at San Pedro,
and is now in the United States National Museum.
Pleistocene. — San Pedro (Arnold).
170. Pleurotoma (Dolichotoma) tryoniana Gabb.
Pleurotoma ( Siircula) tryo7iiana Gabb, Pal. Cal., Vol. II, p. 6, PI. I, fig. 9, 1869.
Sicrcula t>yoyiiana Gabb, Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 266.
Shell resembles P. carpenteriana in shape; whorls eight, convex anterior to middle, with
row of nodes on angle; upper portion of whorls concave; surface ornamented with revolving ridges,
rather coarser on lower portion of whorl; suture impressed; aperture elongate, narrow, widest in
middle; outer lip thin, bulging below the wide, shallow sinus; inner lip smooth; canal short, broad.
Dimejisiojis. — Long. 75 mm.; lat. 28 mm.; body-whorl 52 mm.; aperture, including canal,
40 mm.; defl. 33 degrees.
Distinguishable by nodose, convex, angular whorls.
Rare in upper San Pedro series of San Pedro. Mrs. Oldroyd has several
specimens of this species, which have been hauled up alive in the fishermen's nets at
San Pedro.
Living. — San Diego (Cooper): San Pedro (Oldroyd).
Pleistocene. — Santa Barbara; San Pedro (Cooper): San Pedro (Arnold).
204 CALIFORNIA ACADEMY OF SCIENCES.
Genus Drillia Gray.
Shell turriculated; aperture oval, oblique; canal short, twisted; columella lip strongly
callous above.
Pletiratoma (jibhosa Kiener is a characteristic species.
171. Drillia cancellata Carpenter.
Drillia canal/afa Cv^., Brit. Assn. Rept., 1863, p. 658; Proc. Phil. Acad. Nat. Sci., 1865, p. 63.
Tryon, Man. Conch., Vol. VI, p. 183, 1884.
Shell resembles D. hiermis in shape; whorls eight or nine, nearly flat, but slightly angulaled
near anterior margin; decoration consists of five to six spiral ridges and about twenty-five rather
more prominent transverse, slightly oblique ribs, the whole giving the whorls a cancellated appear-
ance; suture impressed, distinct; canal long, prominent.
The four specimens found were youug, and no adult lias so far been recorded
from this formation.
Found in the lower San Pedro series of Deadman Island, and in the upper
San Pedro series of Los Cerritos. Found in the Pleistocene at Spanish Bight,
San Diego.
Living. — Puget Sound (Carpenter).
Pleistocene. — San Pedro; San Diego (Arnold).
172. Drillia hemphilli Stearns.
' Plate V, Fio. 8.
Drillia hemphilli Stearns, Proc. Cal. Acad. Sci., Vol. V, 1874, p. 80, PI. I, fig. 3. Tryon, Man.
Conch., Vol. VI, p. 185, PI. XIII, fig. 49, 1884.
Shell small, elongate, slender; apex acute; whorls eight, slightly convex, with fifteen
distinct, transverse, slightly oblique, rounded ribs; flat anterior sutural riblet about one-fifth the
width of whole whorl; suture impressed, distinct; spiral sculpture consists of a few faint grooves;
outer lip thin, bulging anteriorly below posterior sinus, which is deep and narrow; anterior sinus
short; inner lip and inner side of columella incrusted.
Dimetisions. — Long. i6nmi.; lat. 5 mm.; body-whorl 8 mm.; aperture, including canal,
5.5 mm.; defl. 20 degrees.
The speciinen described is the largest one found, the normal length being
about 10 mm. Distinguishable by its small size, prominent sutural riblet, and
oblique transverse ridges.
Found in lower San Pedro series of Deadman Island and San Pedro, and in
the upper San Pedro series of Los Cerritos, San Pedro, and Crawfish George's.
Found in the Pleistocene at Barlow's ranch, Ventura; and at Spanish Bight and
Twenty-sixth Street, San Diego. The specimen figured is from the upper San Pedro
series at San Pedro, and is now in the collection of Delos Arnold.
Living. — Lower California (Stearns).
Pleistocene.— ^an Pedro; Ventura (Arnold): San Diego (Stearns; Arnold;
Hemphill).
ARNOLD — THE PALEONTOLOGY AND STKATIGEAPHY OF SAN PEDRO. 205
[S. D.] Drillia incisa Carpenter.
Drillia incisa CpR., Brit. Assn. Rcpt., 1863, p. 657. Cooper, 7th Ann. Rept. Cal. St. Min.,
1888, p. 239.
Shell like D. inermis, except that the spiral sculpture consists of several impressed grooves.
Found in the Pleistocene at Pacific Beach, San Diego.
Living. — Straits of Fiica to Santa Cruz (Cooper).
Pleistocene. — Santa Barbara to San Pedro (Cooper): San Diego (Arnold).
173. Drillia inermis Hinds.
Plate V, Fig. 10.
Pleurotoma inermis Hds., Proc. Zool. Soc, 1843, p. 37; Voyage Sulphur, p. 16, PL V, fig. 8, 1844.
Drillia inermis Hds., Cpr., Brit. Assn. Kept., 1863, p. 657. Gabb, Pal. Cal., Vol. II, p. 72, 1869.
Tryon, Man. Conch., Vol. VI, p. 182, PI. XII, figs. 40 and 43; PI. XXXII, fig. 42,
1884. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 239.
Shell elongate, slender; spire elevated; apex acute; whorls eight or nine, slightly angulated
a little posterior to middle, the posterior portion being slightly concave, and the anterior portion
slightly convex; ornamentation consists of nine to eleven rounded, spiral ridges, and numerous
prominent transverse ridges following th.e lines of growth, which are convexly angulated on the
angle of whorl; the ornamentation is more prominent on the lower portion of the whorls; suture
impressed, distinct; aperture elliptical; outer lip thin, arcuate anteriorly; posterior sinus shallow;
anterior sinus rather long; inner lip and inner portion of columella incrusted; columella slightly
recurved.
Dimensions. — Long. 30 mm.; alt. 9 mm.; body-whorl 17 mm.; aperture, including canal,
II. 5 mm.; defl. 22 degrees.
Distinguishable from D. penicillata by longer canal, angulation of whorls, and
greater prominence of ornamentation; distinguishable from D. cancellata by less
deflection and angulation of whorl, except body-whorl, which is more evenly convex
than in the latter.
Rare in lower San Pedro series of Deadman Island, and in the upper San
Pedro series of Los Cerritos and San Pedro. The specimen figured is from the
upper San Pedro series at San Pedro, and is now in the collection of Delos Arnold.
Found in the Pleistocene at Barlow's ranch, and the old irrigating ditch, Ventura;
and at Spanish Bight and Pacific Beach, San Diego.
Living. — Santa Barbara to San Diego; Lower California (Cooper).
Pleistocene. — Santa Barbara (Cooper): San Pedro; San Diego; Ventura
(Arnold).
174. Drillia inermis var. penicillata Carpenter.
Drillia penicillata CpR., Brit. Assn. Rept., 1863, p. 658; Jour, de Conch., Vol. XIII, 1865, p. 146.
Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 239. Keep, West Coast Shells, p. 56,
fig. 38, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 208.
Pleurototna penicillata Cpr., Tryon, Man. Conch., Vol. VI, p. 1S2, PI. XII, fig. 40, 1884.
Shell elongated; spire elevated; apex acute; whorls eight, only slightly convex; ornamented
with numerous nearly obsolete, rounded, spiral ridges, and fine incremental lines which, reproducing
206 CALIFORNIA ACADEMY OF SCIENCES.
the outline of the lip and posterior sinus, form in the middle of the whorl an angle open anteriorly;
transverse ornamentation more prominent on apical whorls; suture impressed, distinct; aperture
elliptical; outer lip thin, arcuate anteriorly; posterior sinus shallow, wide; anterior sinus short;
columella slightly curved to left; spirally ridged.
Dimensions. — Long. 26.5 mm.; lat. 9 mm.; body-whorl 14.5 mm.; aperture including
canal, 11 mm.; defl. 22 degrees.
Distinguishable by the beautiful wavy incremental lines, which are quite
l^rominent in most specimens. Some of the shells reach a length of 40 mm. (jrades
imperceptibly into D. inennis.
Not uncommon in the lower San Pedro series at Deadman Island and San
Pedro, and in the upper San Pedro series at Deadman Island, San Pedro, Los
Cerritos, Long Beach, and Crawfish George's. Found in the Pleistocene at Spanish
Bight and Pacific Beach, San Diego; and at the old irrigating ditch and Barlow's
ranch, Ventura.
Living. — San Pedro, south; Cerros Island; Lower California (Cooper).
Pleistocene. — San Pedro to San Diego (Cooper): San Pedro (Arnold).
175. Drillia johnsoni, sp. nov.
Plate VIII, Fig. 17.
Shell of medium size, turreted; whorls eight or nine, nearly flat, each crossed by about
thirteen prominent, rounded, equal, equidistant, oblique ribs, which begin at anterior portion of whorl
and extend for about two-thirds distance across whorl, where they become nearly obsolete; a sutural
band occupies the upper third of the whorl; lower portion of whor! with five deep, channel-like
sulcations; sutural band with strong, oblique incremental lines; suture appressed, undulating;
aperture subelliptical; outer lip arcuate; posterior sinus narrow, rather deep; anterior sinus short,
recurved; columella incrusted; body-whorl convex, extended below, with revolving sulcations on
lower portion; transverse ridges obsolete on lower portion.
Diynensions — Alt. 32 mm.; lat. 11 mm.; body-whorl 16. 8 mm.; aperture, including canal,
12 mm.; canal 2 mm.; defl. 25 degrees.
Resembles P. montereyensis, but is distinguishable by larger size, less promi-
nent but more sculptured sutural band, longer and more oblique ribs, and more
numerous spiral sulcations. Distinguishable from P. aurantia by much larger size,
more prominent and more sculptured sutural band, more distinct spiral sulcations,
longer and less oblique aperture, and a recurved rather than a straight anterior
sinus. Pronounced a new species by Dr. Dall. Named in honor of Henry R.
Johnson of Washington, D. C, who has prepared many of the drawings used in
illustrating this paper.
Type specimen from upper San Pedro series of San Pedro. The specimen
figured is the type, which is now in the United States National Museum. Found
also in the upper San Pedro series at Deadman Island by W. B. Barber.
Pleistocene. — San Pedro (Arnold; Barber).
ARNOLD -THE PALEONTOLOGY AND STKATIGKAPHY OF SAN PEDRO. 207
176. Drillia merriami, sp. no v.
Plate VIII, Fig. 7.
Shell small, fusiform, rather thin; ape.x blunt; whorls seven, somewhat angular, with about
fourteen slightly oblique, prominent, rather sharp transverse ridges; these ridges are most prominent
on angle of whorl, and become obsolete near anterior margin and at about one-third width of whorl
from posterior margin; a narrow sutural band occupies upper one third of whorl; incremental lines
visible; suture deeply impressed, distinct; body-whorl somewhat ventricose and narrowed anteriorly,
with transverse ribs sometimes obsolete; aperture broadly elliptical, narrowed anteriorly to a promi-
nent sinus; posterior sinus small, near suture; outer lip arcuate, thin; columella smooth.
Ditnenst07is. — Long. 14.2 mm.; lat. 5.2 mm.; body-whorl 7.6 mm.; aperture, including
canal, 6 mm.; canal 1.5 mm.; defl. 31 degrees.
Thi.9 species somewhat resembles Borsonia hartschi, bat may be distinguished
by lack of columellar plait, longer but less oblique transverse ridges, and narrower
sutural band. Distinguishable from I), hemphilli by lack of spiral sulcations, less
oblique ribs, much longer body-whorl, and much more prominent canal. Dis-
tinguishable from D. torosa by lack of sjiiral lines, narrower sutural band, less convex
whorls, and more and longer ribs. This species is said by Dr. Dall to be near the
Panama species B. pallida Sby. Named in honor of Dr. John C. Merriam, Pro-
fessor of Paleontology in the University of California, who has assisted the writer in
many ways in the jDreparation of this paper.
Rare in Pliocene and lower San Pedro series of Deadman Island. The
specimen figured is the type, which is from the lower San Pedro series at Deadman
Island, and is now in the United States National Museum.
Pleistocene. — San Pedro (Arnold).
Pliocene. — San Pedro (Arnold).
177, Drillia montereyensis Stearns.
Pkurotoma (Drillia) mojiiereyensis Stearns, Proc. Cal. Acad. Sci., Vol. V, 1873, p. 80, PI. I,
fig. 21. Tryon, Man. Conch., Vol. VI, p. 184, PI. XII, fig. 30, 1884.
Shell small, elongate, slender; seven moderately rounded whorls, upper portion of volutions
concavely angulated and ornamented with fine spiral ribs and furrows; middle of upper whorls and
upper part of body- whorl displaying fifteen equidistant, longitudinal, nodose, slightly oblique ribs;
on the smaller volutions of the spire a puckering at and following the suture suggests a second
indistinct series of nodules; aperture less than half the length of shell; canal short; posterior sinus
rather broad, rounded and of moderate depth.
Dimensions. — Long. 15 mm.; lat. 6 mm.; body-whorl 8.4 mm.; aperture 6 mm.; defl.
22 degrees.
Resembles a large D. liemphilli in shape, but has a very distinctive orna-
mentation.
Rare in the lower San Pedro series at Deadman Island; of the two specimens
found, one was obtained by Mrs. Oldroyd.
Living. — Monterey (Stearns).
Pleistocene. — San Pedro (Oldroyd; Arnold).
208 CALIFORNIA ACADEMY OF SCIENCES.
178. Drillia pudica Hinds.
Plate VIII, Fig. 13.
Pleurotoma pudica Hds., Proc. Zool. Soc, 1843, p. 41; Voyage Sulphur, p. 20, PI. VI, fig. 11, 1844.
Cpr., Brit. Assn. Rept., 1856, p. 330. Tryon, Man. Conch., Vol. VI, p. 189,
Pi. XIII, fig. 55, 1884.
Shell small, resembling D. torosa in general appearance; whorls seven, angular, convex
below, concave above, with twelve or thirteen transverse ribs, nearly all of which extend from suture
to suture, but less prominent on the concave surface; surface spirally sulcate; in other respects
similar to torosa.
DimensioJis. — Long. 11 mm.; lat. 4 mm.; defl. 25 degrees.
Distinguishable from I), torosa by the long transverse ribs, and by the more
convex outline of the whole shell. Specimen identified by Dr. Dall.
Rare; one specimen from upper San Pedro series of San Pedro, which
is figured, and is now in the collection of Delos Arnold.
Living. — Central America (Carpenler).
Pleistocene. — San Pedro (Arnold).
179. Drillia renaudi, sp. nov.
Platk VIII, Fig. 5.
Shell small, fusiform, turreted; apex blunt; whorls eight, sharply angular, with angle about
two-fifths distance from anterior margin of whorl; upper and lower surfaces flat; about fifteen oblique
nodes ornament the angle and extend down on the lower portion of the whorl, becoming obsolete
before reaching the suture; nodes obsolete on body-whorl; suture deeply impressed, distinct;
aperture short, elliptical, oblique; posterior sinus broad, shallow; anterior sinus long, straight;
columella incrusted within; body-whorl angular, ventricose, much produced and narrow below,
smooth, except for very faint incremental lines.
Dimensions. — Long. 15.8 mm.; lat. 6 mm.; body-whorl 9 mm.; aperture, including canal,
7 mm.; canal 2 mm.; defl. 35 degrees.
Different in shape from any other member of this genus found in these
deposits. Distinguishable by the smooth, ventricose body-whorl, sharply angulated
whorls, nodose angle, and long canal. This species has the long canal of D. perversa,
the angular whorls of Leucosyrinx pedroana, and the nodes, though less prominent,
of I), torosa. Specimens pronounced a new species by Dr. Dall. Named in
honor of Ralph E. Renaud, who has prepared many of the drawings which illustrate
this paper.
Rare; one specimen from Pliocene and one (type) from lower San Pedro
series of Deadman Island. The specimen figured is the type, which is now in the
United States National Museum.
Pleistocene. — San Pedro (Arnold).
Pliocene. — San Pedro (Arnold).
ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 209
i8o. Drillia torosa Carpenter.
Drillia torosa Cpr., Brit. Assn. Rept., 1863, p. 657;Jour. de Conch., 3id Ser., Vol. XV, 1865, p. 145.
Tryon, Man. Conch., Vol. VI, p. 183, Pi. XIV, fig. 93, 1884. Cooper, 7th Ann. Rept.
Cal. St. Min., 18S8, p. 239. Keep, West Coast Shells, p. 56, fig. 59, 1892. William-
son, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 298.
Shell elongated; spire elevated; apex acute; whorls eight, angulated near middle, with row
of about nine nodes, transversely elongated, on angle; the upper portion of whorl flat to concave;
anterior half of whorl spirally striated; incremental lines visible, oblique, and on upper part of whorl,
concave anteriorly; suture impressed, distinct; lower portion of body- whorl and columella spirally
striated; aperture elliptical; outer lip thin and arcuate anteriorly; inner lip and columella slightly
incrusted; posterior sinus shallow; anterior sinus short, straight.
Dimensions. — Long. 25 mm.; lat. 8 mm.; body-whorl 14.5 mm.; aperture, including
canal 9.5 mm.; defl. 22 degrees.
Distinguishable by the nodose whorls. The relative length of canal varies
somewhat in thi.s species, as does also the prominence of the nodes.
Found in the Pliocene at Deadraan Island and Timm's Point; in the lower
San Pedro series at Deadman Island and San Pedro; and in the upper San Pedro
series at Deadman Island, San Pedro, Los Cerritos, and Crawfish George's. Most
common in the lower formations.
Living. — Santa Cruz to Santa Barbara (Cooper): San Pedro (Williamson).
Pleistocene. — Santa Barbara (Cooper): San Pedro (Arnold).
Pliocene. — San Pedro (Arnold).
Genus Bela Gray.
Shell oval, fusiform, thin; spire produced; canal short; sinus small, near the suture; columella
flattened; operculum pointed at both ends.
Pleurotoma turricula Montf. is a characteristic species.
181. Bela fidicula Goidd.
Plate VII, Fig. 10.
Fusus Jidicuia Gi^u., Proc. Bost. Soc. Nat. Hist., Vol. Ill, 1849, p. 142; Wilkes' Expl. Exped.,
Vol. XII, p. 233, fig. 284, 1852.
Be/a fidicula Gi^Y)., CpR., Brit. Assn. Rept., 1863, p. 658. Tryon, Man. Conch., Vol. VI, p. 222,
PI. XXXII, fig. 17, 1884.
Shell small, thin, turreted, short, fusiform; whorls seven, angular, forming a broad shoulder at
the suture; surface sculptured with delicate, regular, obtuse, transverse rib-folds, about twenty-four
on the last whorl, on the middle of which they disappear, decussated by more crowded, delicate
grooves, a little undulating, about eight on the penultimate whorl; suture deeply impressed, distinct;
aperture narrow, elliptical; outer lip thin, slightly arcuate; pillar smooth interiorly, spirally striate
externally; canal short.
Dimensions. — Long. 10 mm.; lat. 4.1 mm.; body-whorl 6.8 mm.; aperture 5 mm.; defl.
30 degrees.
Found in Pliocene at Deadman Island, lower San Pedro series at Deadman
Island, and upper San Pedro series at Crawfish George's. Found also in the Pleistocene
( 27 ) March 14, 1903.
210 CALIFORNIA ACADEMY OF SCIENCES.
in bluff west of bath-house, Santa Barbara, and at old irrigating dittdi, Ventura. The
specimen figured is from the lower San Pedro series at Deadman Island, and i.s now
in the collection of Delos Arnold.
Living. — Puget Sound (Carpenter).
Pleistocene. — San Pedro; Santa Barbara; Ventura (Arnold).
Pliocene. — San Pedro (Arnold).
182. Bela sanctce-monicae, sp. nov.
Plate VIII, Fig. 14.
Shell small, broadly fusiform; spire elevated; apex subacute; whorls five, convex, slightly
angular above, with about sixteen prominent, rounded ribs, which extend from suture to suture;
surface sculptured with spiral sulcations; suture deeply impressed, distinct; aperture slightly oblique,
subelliptical; canal short; body-whorl ventricose, lacking transverse sculpture on lower portion;
pillar smooth.
Dimensio7is. — Long. 12 mm.; lat. 7.5 mm.; body-whorl S.5 mm.; aperture, including canal,
6.8 mm.; canal i mm.; defl. 50 degrees.
Distingui.shable from B.fidicula by much broader form, fewer and less sharply
angular whorls, and more ventricose body-whorl, and less elevated spire. The type
specimen was examined by Dr. Dall, who pronounced it a new species.
Type from lower San Pedro series (Pleistocene) at Port Los Angeles, near
Santa Monica. Five specimens of the same species, with slightly more angulated
whorls, were found in the lower San Pedro series of Deadman Island. The specimen
figured is the type, which is now in the United States National Museum.
Pleistocene. — San Pedro; Port Los Angeles (Arnold).
Genus Mangilia (Leach) Bisso.
The present genus includes all P leiirotomidce without opercula.
Subgenus Clathurella Carpenter.
Shell fusiform or turriculated; columella lip without callosity, except a small posterior tooth;
no operculum; the cancellated surface, more ventricose form, and more evident canal, distinguish it
from Mangilia; the emargination of the outer lip from C/avalit/a; the texture and sculpture of the
surface from Bela and Daphnella.
Pleurotoma luLenris Blainv. is a characteristic species.
1.83. Mangilia (Clathurella) conradiana Gahb.
ClathiDclla conradiana Gabb, Pal. Cal., Vol. II, p. 7, PI. I, fig. 12, 1869. CooPER, 7lh Ann. Rept.
Cal. St. Min., 1888, p. 235.
Shell small, robust, broadly fusiform; spire high, whorls seven, the first smooth and round,
the remainder angulated, concave above, convex below; surface ornamented by ten or twelve rounded
transverse ribs, crossed by square elevated ribs, with sometimes smaller ones interposed; on the upper
ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OP SAN PEDRO. 211
or concave part of whorl are several fine, revolving lines; suture deeply impressed, distinct; aperture
long, narrow; posterior sinus near suture deep, prominent; anterior sinus short, recurved; outer lip
arcuate; pillar straight, spirally striate.
Dimensions. — Long. 11.5 mm.; lat. 4.5 mm.; body-whorl 6.9 mm.; aperture 5.5 mm.; defl.
35 degrees.
X)istingiiisliable by deep posterior sinus from other members of the same
family. (Originally tiescribecl from Pleistocene specimen.) Pronounced as "near
C. canjieldii Dall," by Dr. Dall.
Rather common in the Pliocene and lower San Pedro series of Deadman
Island; rare in the lower San Pedro series and upper San Pedro series of San Pedro.
Found in the Pliocene at Packard's Hill; and in the Pleistocene at the bath-house,
Santa Barbara.
Living. — San Pedro (Raymond).
Pleistocene. — Santa Barbara (Cooper): San Pedro; Santa Barbara (Arnold).
Pliocene. — San Pedro; Santa Barbara (Arnold): San Diego well (Dall).
Subgenus Cythara Schumacher.
Shell fusiform, polished, longitudinally ribbed; aperlure linear, truncated in front, slightly
notched behind; outer lip margined, denticulated within; inner lip frequently finely striated.
Pleurotoma stromboides Reeve is a characteristic species.
184. Mangilia (Cythara) branneri, sp. nov.
Plate IX, Fig. 10.
Shell small, fusiform; spire elevated; apex rounded; whorls six; slightly convex, with six
sharp, slighdy oblique, transverse ribs arranged in slightly twisted lines radiating from the apex;
suture impressed, distinct; aperture narrow, truncated in front, slightly notched behind; outer lip
margined; inner lip smooth.
Dimensions. — Long. 10 mm.; lat. 4 mm.; body-whorl 6 mm.; aperture 4.5 mm.; defl.
27 degrees.
Distinguishable by the few longitudinally connected, sharp, radiating ridges.
Pronounced by Dr. Dall as probably being new. Named in honor of Dr. John C.
Branner, Professor of Geology in Leland Stanford Jr. University.
Rather common in lower San Pedro series of Deadman Island. Found also
in the Pleistocene at bath-house, Santa Barbara. The specimen figured is the type,
which is from the lower San Pedro series at Deadman Island, and is now in the
United States National Museum.
Pleistocene. — San Pedro; Santa Barbara (Arnold).
Subgenus Mangilia Risso, s. s.
Fusiform, mostly longitudinally ribbed, spire elongated, turriculated, acuminated; canal short,
more or less truncated; columella smooth; sinus near the suture. No operculum.
Pleurotoma ponderosa Reeve is a characteristic species.
212 CALIFORNIA ACADEMY OF SCIENCES.
185. Mangilia angulata Carpenter.
Plate VII, Fig. 9.
Mangilia angulata CpR., Brit. Assn. Rept., 1863, p. 658; Ann. & Mag. Nat. Hist., 3rd Ser. , Vol.
XV, 1865, p. 395. Keep, West Coast Shells, p. 55, 1892. Cooper, Bull. No. 4, Cal.
St. Min. Bureau, 1894, Part 3, p. 27.
Shell small, turreted, elongate- fusiform; apex acute; whorls six, broad and angular, angle
being slightly posterior to middle; sculpture consists of ten prominent, rather sharp, transverse
ridges which reach maximum prominence on angle of whorl; suture deeply impressed, distinct,
aperture oblique, narrow, elliptical, drawn out anteriorly into a short, narrow canal; outer lip thin;
simple, arcuate; inner lip smooth.
Dimensions. — Long. 8 mm.; lat. 3.2 mm.; body- whorl 5 mm.; aperture 4 mm.; defl.
33 degrees.
Some of the shells show a very faint spiral sculpture. Distinguishable by
broad form and simple transverse sculpture. Specimens identified by Dr. Dall.
Many sj^ecimens of this species in the State museum collection of fossils at
Berkeley are labeled "il/. variegata."
Rather common in the lower San Pedro series of Deadman Island and San
Pedro; rare in the upper San Pedro series at Crawfish George's and Los Cerritos.
Found also in the Pleistocene at bath-house, Santa Barbara; Barlow's ranch, A^en-
tura, and at Spanish Bight and Pacific Beach, San Diego. The specimen figured
is from the lower San Pedro series at Deadman Island, and is now in the collection
of Delos Arnold.
Living. — Puget Sound to Santa Barbara (Carpenter).
Pleistocene. — San Pedro (Arnold): San Joaquin Bay, Orange County
(Bowers): Santa Barbara; Ventura; San Diego (Arnold).
186. Mangilia hooveri, sp. nov.
Plate IX, Fig. 5.
Shell small, elongate-fusiform, solid; spire elevated; apex mammilliform; whorls six, only
slightly convex, with about ten low, rounded, slightly oblique, transverse ridges; the first whorl is
smooth, while the next three are more convex than the lower ones, and have traces of spiral sculp-
ture; body-whorl with sculpture nearly obsolete; aperture elliptical, tapering to a very short canal
anteriorly; outer lip arcuate, thin; pillar quite long and straight.
Dimensions. — Long. 10.9 mm.; lat. 3 mm.; body-whorl 6 mm.; aperture 4 mm.; defl.
20 degrees.
Distinguishable by the slender form, nearly flat whorls, and the broad, low,
transverse ridges. The body-whorl resembles that of a small, elongate-j^illared DriUia.
Pronounced new by Dr. Dall. Named in honor of Mr. T. J. Hoover of Stanford
University, California.
Type from upper San Pedro series of San Pedro; rare. The specimen figured
is the type, and is now in the United States National Museum.
Pleistocene. — San Pedro (Arnold).
ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 213
187. Mangilia interfossa var. pedroana, var. nov.
Plate VI, Fig. 3.
Majigilia iti/er/ossa Cpr., Brit. Assn. Rept., 1863, p. 658; Ann. & Mag. Nat. Hist., 3d Ser., Vol.
XV., 1865, p. 29.
Daphnella mterfossa Cpr., Tryon, Man. Conch., Vol. VI, p. 310, PI. XXII, fig. 11, 1884.
Shell small, turreted, elongate-fusiform; apex acuminate; whorls six, convex, ornamented
with about sixteen rounded, slightly oblique, transverse ridges and four to six sharp, raised, spiral
lines in the interspaces; suture deeply impressed; aperture narrow, slightly oblique, elliptical; outer
lip thin, simple; inner lip smooth.
Dimensions. — Long. 7.5 mm.; lat. 2.5 mm.; body-whorl 4.1 mm.; aperture 2.8 mm.; defl.
30 degrees.
Distinguishable from M. inter lirnta by broader form, more convex whorls, and
more numerous lines of sculpture. Specimens pronounced new variety of M. inter-
fossa by Dr. Dall.
Rare in lower San Pedro series at Deadraan Island; and in upper San Pedro
series at Crawfish George's. Found also in the Pleistocene at bath-house, Santa
Barbara. The specimen figured is the type, which is from the lower San Pedro series
at Deadman Island, and is now in the United States National Museum.
Pleistocene. — San Pedro; Santa Barbara (Arnold).
188. Mangilia interlirata Stearns.
Plate VI, Fig. 15.
Mangilia interlirata BTTS.Av.iiS, Proc. Cal. Acad. Sci., Vol. IV, 1872, p. 226, PI. I, fig. 10. Tryon,
Man. Conch., Vol. VI, p. 249, PI. XXII, fig. 56, 1884.
Shell small, elongate, fusiform; spire much elevated; apex acute; whorls six, slightly con-
vex, ornamented by nine or ten slightly oblique, rather narrow, transverse ridges; spiral sculpture
consists of three or four sharp raised lines, which extend to base of body-whorl; suture impressed,
distinct; aperture narrow, elliptical; outer lip thin, simple; inner lip simple; canal simple.
Dimensions. — Long. 8.8 mm.; lat. 3 mm.; body-whorl, 4.9 mm.; aperture, 3 mm.; defl.
25 degrees.
Distinguishable from M. interfossa var. 'pedroana by its slenderer outline,
fewer transverse and spiral ridges, and flatter whorls; distinguished from others of
the genus by the prominence of its spiral lines. Specimens identified by Dr. Dall.
Rare in lower San Pedro series at Deadman Island, and in the upper San
Pedro series at Los Cerritos. The specimen figured is from the Lower San Pedro
series at Deadraan Island, and is now in the collection of Delos Arnold.
Living. — West Coast.
Pleistocene. — San Pedro (Arnold).
189. Mangilia oldroydi, sp. nov.
Plate VI, Fig. 16.
Shell small, turreted, elongate-fusiform; apex acuminate; whorls seven, convex, rather
shouldered above, and crossed by sixteen slightly oblique rounded ridges; transverse ridges become
214 CALIFORNIA ACADEMY OF SCIENCES.
obsolete on lower hall" of body-vvhorl; spiral sculpture consists of three or four fine raised lines on
lower portion of whorl and several microscopic lines on upper portion; the spiral sculpture is more
prominent on the body-whorl; suture deeply impressed; aperture narrow p)'riform, drawn out on
anterior end to a long, narrow, recurved canal; outer lip arcuate, thin, simple; inner lip smooth.
Dimensions. — Long. 16 mm.; lat. 6 mm.; body-whorl 10 mm.; aperture 8 mm.; defl.
38 degrees.
The largest and finest of the Pleistocene MnngUve. Distinguishable by its
large size, rounded ridges, faint shouldered appearance of the whorls, and long,
recurved canal. " Different from any of the species in the Smithsonian collec-
tion " (Dall).
Rare in lower San Pedro series of Deadman Island; one specimen (ty[)e)
collected by Mrs. Oldroyd, which is figured, and is now in her collection.
Pleistocene. — San Pedro (Oldroyd).
190. Mangilia painei, sp. nov.
Plate VIII, Fu:. 1.
Shell small, elongate-fusiform; spire elevated; apex rounded; whorls seven, evenly convex,
with about eleven slightly transverse, rounded ribs, which become obsolete at the sutures; spiral
sculpture obsolete; aperture narrow, elliptical, narrowing anteriorly to canal; canal truncate in front;
posterior sinus small; outer lip arcuate, thin, with faint ridge on interior; suture deeply impressed ;
pillar long, smooth within, obsolete sculpture without.
Dimensions. — Long. 12 mm.; lat. 4.2 mm.; body-vvhorl S mm.; aperture, including canal,
6.1 mm.; canal 1.5 mm.; defl. 32 degrees.
Distinguishable by slender form, evenly convex whorls, prominent transverse
ribs, and obsolete spiral sculpture; canal also longer than in most species. Resembles
7)/. oldroydi in outline, but has no spiral sculpture or angulated whorls. Pronounced
a new species by Dr. Dall. Named in honor of Miss Winifred Mabel Paine of Red-
lands, California, who has drawn many of the figures illustrating this paper.
Not uncommon in the lower San Pedro series of Deadman Island. The
specimen figured is the type, which is from the lower San Pedro series of Deadman
Island, and is now in the United States National Museum.
Pleistocene. — San Pedro (Arnold).
191. Mangilia sculpturata Ball.
Plate VI, Pig. 17.
Be/a sculpturata Dall, Proc. U. S. Nat. Mus., Vol. IX, 1887, p. 299, PI. IV, fig. 7.
Shell small, turreted, elongate- fusiform; apex acute; whorls seven, sharply angulated, with
flat, sloping surfaces both above and below angle; sculpture consists of eight or nine sharp transverse
ridges, and two or three sharp spiral lines on lower portion; aperture very deeply impressed, giving
tabulate appearance to whorls; aperture long, narrow, and drawn out into a long, narrow canal at
anterior end; outer lip thin, simple; inner lip smooth; spiral sculpture extends to base of pillar.
Dimensions. — Long. 10.5 mm.; lat. 3 mm.; body-whorl 6 mm.; aperture 4 mm.; defl.
23 degrees.
ARNOLD — THE PALEONTOLOGY AND STRATIGKAPHY OF SAN PEDRO. 215
A slender, deeply sutured form, with a comparatively long canal; these
characteristics distinguishing it from others of the genus. Specimen identified by
Dr. Dall. ' •
Rare in Pliocene and lower San Pedro series of Deadman Island; one
specimen from each horizon. The specimen figured is from the Pliocene of Dead-
man Island, and is now in the collection of Delos Arnold.
Living. — West Coast.
Pleistocene. — San Pedro (Arnold).
Pliocene. — San Pedro (Arnold).
192. Mangilia striosa 0. B. Adams.
Pl.ATK IX, FiC. .s.
Mangilia striosa C. B. Ads., Ann. N. Y. Lye. Nat. Hist., Vol. V, 1852, p. 147. Tryon, Man.
Conch., Vol. VI, p. 249, PL XXXIV, fig. 96, 1884. Williamson, Proc. U. S. Nat.
Mus., Vol. XV, p. 208, 1892.
Shell small, elongate-fusiform; spire much elevated; ape.x acute; whorls six, subangular,
with numerous fine, slightly wavy transverse ridges, which become obsolete at the sutures; spiral
sculpture nearly obsolete; suture very deeply depressed, giving a rather frail appearance to the
spires; aperture narrow, elliptical, tapering anteriorly to a short, truncated canal; posterior sinus
small; outer lip thin, simple, arcuate; columella smooth; straight on anterior portion.
Dimensions. — Long. 9.2 mm.; lat. 3 mm.; body-whorl 5.2 mm.; aperture 4 mm.; defl.
22 degrees.
This species is distinguishable by its numerous fine, transverse ridges, deep
suture, subangular whorls, and slender form. Resembles M. sciilpttiraia somewhat in
outline, but has less angular whorls and more numerous, finer ribs. Distinguishable
from 2/. oldrnijdi by the angle being nearer the middle of the whorl, the ridges being
finer, the pillar .shorter, and the suture deeper. Specimens identified by Dr. Dall.
Rare in upper San Pedro series of San Pedro and Los Cerritos. Found also
in Pleistocene at Spanish Bight, San Diego. The specimen figured is from the upper
San Pedro series at Los Cerritos, and is now in the collection of Delos Arnold.
Living. — Panama (Carpenter): San Pedro (Williamson).
Pleistocene. — San Pedro; San Diego (Arnold).
Subgenus Taranis Jeffreys.
Shell minute, cancellated; whorls angulated, slightly exserted at base; aperture pyriform;
outer lip thin, simple; sinus obsolete; canal short.
l^arnnis morchii Malm, is a characteristic species.
193. Mangilia (Taranis) strongi, sp. nov.
Plate IX, Fig. 7.
Shell small, elongated; spire elevated; apex mammilliform; whorls six, angulated near
middle, upper surface concave, lower surface convex; two strong spiral ridges, one on angle, the
216 CALIFORNIA ACADEMY OF SCIENCES.
other in middle of lower portion of whorl; incremental lines visible; suture impressed, distinct;
aperture subovate, oblique; outer lip thin, slightly arcuate anteriorly; inner lip smooth; posterior
sinus broad, very shallow; anterior sinus short; columella short, distinct.
Dimensions. — Long. 12 mm.; lat. 5.5 mm.; body-whorl 7 mm.; aperture 5 mm.; defl.
38 degrees.
Distinguishable from others of the same family by the two strong, revolving
ridges. Named in honor of A. M. Strong. Specimens pronounced new species by
Dr. Dall.
Rare in the lower San Pedro series of San Pedro and Deadraan Island; found
also in the Pliocene of Deadman Island, and in the upper San Pedro series at Craw-
fish George's. The specimen figured is the type, which is from the lower San Pedro
series at Deadman Island, and is now in the United States National Museum.
Pleistocene. — San Pedro (Arnold).
Pliocene. — Santa Monica; San Pedro (Arnold).
Subgenus Spirotropsis Sars.
Shell elongate, turreted, spire produced; the obtuse apex mammilliform; whorls numerous,
carinated in the middle; aperture narrow, oblique, with a short canal; sinus deep; remote from
suture.
Plmrotoma carinatn Phil, is a characteristic species.
194. Pleurotoma (Spirotropsis) smithi, sp. nov.
Platk VI, Fig. 13.
Shell elongate, turreted, slender; spire elevated; apex obtuse, mammilliform; whorls ten,
convex, with a slight tendency toward angulation on the lower third of the whorl, and abruptly
terminated at the posterior margin; suture very deeply impressed, distinct; sculpture consists simply
of oblique, incremental lines, which are quite deeply angulated convexly, posteriorly just a little above
the middle of the whorl; aperture narrow, oblique; outer lip thin, arcuate anteriorly; inner lip smooth
and incrusted; posterior sinus deep and remote from suture; canal narrow, slightly recurved, over
one-third of the aperture.
Dimensio7is. — Long. 35 mm.; lat. 11 mm.; body-whorl 8.5 mm.; aperture 13 mm.; defl.
19 degrees.
A long, slender species, slightly resembling the sinistral P. perversa in general
outline, but easily distinguishable from that species and also from all the other
members of this family. Some of the shells are a little more depressed than the tyjie.
Specimens identified by Dr. Dall as being a new species.
Not uncommon in tiie lower San Pedro series and Pliocene of Deadman
Island. The specimen figured is the type, which is from the Pliocene of Deadman
Island, and is now in the United States National Museum.
Living. — (Locality not mentioned) (Dall).
Pleistocene. — San Pedro (Arnold).
Pliocene. — San Pedro (Arnold).
AKNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 217
Family LIII. CANCELLARIID^.
Genus Cancellaria Lamarck.
Subgenus Cancellaria s. s.
Shell oval, cancellated; last whorl ventricose; aperture oblong, canaliculated in front; canal
short, sometimes recurved; columella with several large oblique plications.
Type, Cancellaria cancellata Linn.
195. Cancellaria cooperi Gahh.
Plate VII, Fig. 8.
Cancellaria {Narona) cooperi Ga.'r^, Proc. Cal. Acad. Sci., Vol. Ill, 1865, p. 186.
Cancellaria cooperi Gabb, Tryon, Man. Conch., Vol. VII, p. 76, PI. IV, fig. 66, 1885. William-
son, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 211, PI. XXII, fig. 2.
Shell fusiform; spire elevated, about one-third length of shell; apex subacute; whorls six to
seven, angulated, concave above, convex below; lower portion of whorl with ten to fourteen promi-
nent, rounded, slightly oblique ribs which end in tubercles on angle; lower part of whorl ornamented
with close-set spiral ridges, alternating in prominence; ridges on upper part of whorl less prominent;
body-whorl ventricose and crossed by raised incremental lines; suture appressed, wavy, distinct;
aperture seniielliptical; outer lip not thickened, denticulated; inner lip heavily incrusted, and with
two sharp, oblique pHcations on lower part; columella slightly twisted, rough; canal short.
Dimensions. — Long. 80 mm.; lat. 35 mm.; body-whorl 56 mm.; aperture, including canal,
35.5 mm.; defl. 40 degrees.
Rare in the upper San Pedro series of San Pedro; five specimens found.
Mrs. Oldroyd has a fine living specimen of this species which was hauled up in
the fishermen's nets at San Pedro. The specimen figured is from the upper San
Pedro series at San Pedro, and is now in the collection of Delos Arnold.
Living. — Monterey to San Diego (Cooper): San Pedro (Oldroyd).
Pleistocene. — San Pedro (Arnold).
196. Cancellaria crawfordiana BaU.
Cancellaria crawfordiana Dall, Proc. U. S. Nat. Mus., Vol. XIV, 1891, p. 182, PL VI, fig. i.
Shell small, fusiform; spire elevated; whorls five or six, acutely angulated above near margin;
upper portion flat, forming revolving table; lower portion evenly convex; sculpture very prominent,
cancellated, consisting of about twenty-five nearly straight, equidistant, transverse ribs and about ten
equidistant spiral ridges of equal prominence with the transverse ones; incremental lines visible
between transverse ribs; suture impressed, very distinct; aperture semielHptical; outer lip slightly
thickened and faintly denticulate; inner lip not incrusted; columella with two prominent plications on
the inner side; canal short and broad.
Dimensions. — Long. 37 mm.; lat. 16 mm.; body-whorl 24.5 mm.; aperture, including canal,
17.5 mm.; defl. 38 degrees.
Resembles C. coo])eri in shape, but is distinguishable by the prominent cancel-
lated sculpture.
( 28 ) March 17, 1903.
218 CALIFORNIA ACADEMY OF SCIENCES.
Rare in upper San Pedro series of San Pedro; one specimen found.
Living. — Drake's Bay to San Diego, 20 to 30 fathoms (Dall): San Pedro
(Raymond).
Pleistocene. — San Pedro (Arnold).
197. Cancellaria tritonidea Gabb.
Plate VII, Fig. 5.
Cancellaria irilonidea Gabb, Pal. Cal, Vol. II, pp. ii, 79, PI. II, fig. 18, i86g. Cooper, 7th Ann,
Rept. Cal. St. Min., 1888, p. 231. Dall, Proc. U. S. Nat. Mus., Vol. XIV,
1891, p. 1S3.
Shell large, robust-fusiform; spire elevated, subacute; whorls six, first generally decollated,
angulated; upper part of first three and one-half revolutions convex; upper part of lower whorls
concave; lower part of all whorls, except body-whorl, generally covered with a lamellar incrus-
tation; ten prominent sharp nodes on angle of whorl; whorls ornamented with numerous promi-
nent, squarish, spiral ridges between which are less prominent raised lines; incremental lines
visible, and some of them which pass through the nodes have the prominence of weak varices; suture
appressed, wavy, distinct; aperture subovate; outer lip not thickened; inner lip incrusted; columella
rough, twisted, widened, with two prominent plications on the inner side; canal short, wide.
Dimensions. — Long. 90 mm.; lat. 60 mm.; body-whorl 70 mm.; aperture, not including
canal 50 mm.; defl. 75 degrees.
The shell figured and desci'ibed in this paper is the largest and most nearly
perfect one yet found in this locality. Gabb's tyj^e specimen was beach worn and
not as well preserved as the one described above, which accounts for the lack of the
sharp nodes and more rounded outline of his shell. A specimen in this collection
labeled "Cancellaria vetusta Gabb, Pliocene, Ventura" by Dr. Bowers, is of the same
species. Whether Bowers' specimen came from the Pliocene or Pleistocene is a
matter of doubt.
Dr. Dall pronounced C. tritonidea near to O.cassldiformis Sowerby, and it mav
be one form of this latter variable species.
The young shells of this species are quite variable in regard to the promi-
nence of the nodes, amount of angulation of the whorls, and the shape of the aper-
ture. Any one not possessing a series showing the connection between the two
extremes might think them different species. C. vetusta is probably a precursor of,
if not identical with, C. tritonidea.
Rather rare in the upper San Pedro series of San Pedro. Found also in the
Pleistocene at Barlow's ranch and at old irrigating ditch, Ventura. The specimen
figured is from the upper San Pedro series at San Pedro, and is now in the collec-
tion of Delos Arnold.
Pleistocene. — Coyote Creek, Ventura County; San Pedro (Cooper): San
Pedro; Ventura (Arnold).
AKNOLD — THE PALEONTOLOGY AND STKATIGRAPHY OF 8AN PEDRO. 219
Genus Admete Mailer.
Shell oval, thin, diaphanous, covered by a thin epidermis; spire sharp; last whorl ventricose;
aperture oval, feebly channeled in front, columella arcuated, obliquely truncated, with rudimentary
plications; outer lip sharp.
Admete viridula Fabr. is a characteristic species.
198. Admete gracilior Carpenter.
Plate VII, Fig. 4.
Cancellaria gracilior CpR., Pal. Cal., Vol. II, p. 50, 1869. Cooper, 7th Ann. Rept. Cal. St. Min.,
18S8, p. 23.
Shell small, ovate, thin; spire elevated, subacute; whorls six, rounded to subangular, crossed
by numerous prominent, rounded ridges which reach their maximum prominence on the angle of the
whorl; these ridges become nearly obsolete on the anterior part of the body-whorl; spiral sculpture
consists of numerous fine ridges and furrows; suture deeply depressed, giving shouldered appear-
ance to whorls; aperture ovate; outer lip thin, smooth; inner lip only slightly incrusted; columella
obliquely truncated, and having two plications on inner side; slight umbilical slit; no canal.
Dimensions. — Long, 11 mm.; lat. 6.3 mm.; body-whorl 7.5 mm.; aperture 5.5 mm.; defl.
50 degrees.
A unique form, looking something like a small Fusus robustuti with the canal
gone. It is quite a variable species, one specimen showing a narrower spire and
fewer, but more prominent ribs than the type, while still another showed more
rounded whorls and less prominent ridges.
Found in the lower San Pedro series at Deadman Island. Also obtained from
the Pleistocene at the bath-house, Santa Barbara; and at Port Los Angeles, near
Santa Monica. The specimen figured is from the lower San Pedro series at Dead-
man Island, and is now in the United States National Museum.
Pleistocene.- — San Pedro (Oldroyd; Arnold): Santa Barbara (Carpenter;
Arnold): Santa Monica (Arnold).
Family LIV. OLIVID^.
Genus Olivella Sivuinson.
Shell small, polished; spire produced, acute; suture canaliculated; aperture narrow behind;
enlarged anteriorly; columella plicated in front, callous posteriorly.
Olivella undatella is a characteristic species.
199. Olivella biplicata Suiverbtj.
Olivella biplicata Sby., Tank. Cat., App., p. 33, 1825. Cpr , Brit. Assn. Rept., 1863, p. 661.
H. & A. Adams, Gen. Rec. Moll, p. 146. Gabb, Pal. Cal., Vol. II, p. 75, 1869.
Tryon, Man. Conch., Vol. V, p. 87, PI. XXXIV, fig. 58, 1883. Cooper, 7th Ann.
Rept. Cal. St. Min., 18S8, p. 255. Keep, West Coast Shells, p. 40, fig. 20, 1892.
Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 212 (and varieties).
220 CALIFORNIA ACADEMY OF SCIENCES
Shell small, subcylindrical; spire only slightly elevated; apex subacute; whorls five or six,
flat, smooth, except for very fine incremental lines; suture appressed, very distinct; body-whorl
convex, but nearly flat near outer lip; aperture elongate-triangular; outer lip thin, nearly straight;
inner lip thickly incrusted, the incrustation forming quite a ridge; columella completely incrusted
around lower portion, two prominent plications.
Dime)isions.— "Long. 17.7 mm.; lat. 9.6 mm.; body-whorl 15.7.; aperture 13. i mm.; apical
angle 90 degrees.
This species differs from 0. 2:>edroana in size and comparative width, and from
0. intorta in having two plaits, a greater deflection, and in being much larger.
Common in the lower and upper San Pedro series, and Pliocene of the San
Pedro region. Found also in the Pleistocene at Barlow's ranch and the old irri-
gating ditch, Ventura; at the bath-house, Santa Barbara, and at Spanish Bight and
Pacific Beach, San Diego.
Living. — Straits of Fuca to San Diego (Cooper).
Pleistocene. — Santa Barbara to San Diego (Cooper): San Pedro; Santa
Barbara; Ventura; San Diego (Arnold).
Pliocene. — Seven Mile House; Twelve Mile House; Kirker's Pass; San Diego
well (Cooper): San Pedro (Arnold).
200. Olivella intorta Carpenter.
Olivella ijitorta Cpr., Proc. Zool. Soc, 1856, p. 207. Cooper, 7th Ann. Rept. Cal. St. Min., 1888,
p. 255. Keep, West Coast Shells, p. 42, 1892. Williamson, Proc. U. S. Nat. Mus.,
Vol. XV, 1892, p. 212, PI. XIX, fig. 9.
Shell small, subovate; spire elevated, solid; whorls five, flat, smooth; suture appressed, very
distinct; body-whorl ventricose, smooth; aperture long, narrow, widening anteriorly; outer lip thin;
inner lip incrusted, incrustation thick, forming callus on body of middle whorl near aperture;
columella with smooth incrustation over lower portion, and one prominent, sharp plait on lower side.
Dimensions. — Long. 11. 7 mm.; lat. 6 mm.; body-whorl 9.7 mm.; aperture 7.2 mm.; defl.
60 degrees.
Distinguishable from 0. pedroana by breadth, less elevated spire, greater
deflection, and larger callus on upper part of inner lip; distinguishable from
0. hipllcata by single plait on columella, less deflection and smaller size.
Quite common in the Pliocene and Pleistocene of the San Pedro region; rare
in upper San Pedro series at Los Cerritos. Found in the Pleistocene at Twenty-sixth
Street and Pacific Beach, San Diego; and at Barlow's ranch and the old irrigating
ditch, Ventura.
Living. — Santa Cruz to Lower California (Dall).
Pleistocene. — San Pedro; San Diego (Cooper): San Pedro; Ventura; San
Diego (Arnold).
Pliocene. — San Diego well (Dall).
AKNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 221
201. Olivella pedroana Conrad.
Strepho7ia pedroana Con., Pac. R. R. Rept., Vol. V, p. 327, PI. VI, fig. 51, 1854.
Olivella bwtica Cpr., Brit. Assn. Rept., 1863, p. 661. Gabb, Pal. Cal., Vol. II, p. 75, 1869. Tryon,
Man. Conch., p. 71, PI. XVII, figs. 28, 31, 34, 1883. Cooper, 7th Ann. Rept. Cal. St.
Min., 1888, p. 255. Keep, West Coast Shells, p. 42, fig. 21, 1892. Williamson,
Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 212, PI. XIX, fig. 7.
Shell small, elongate; spire elevated; apex acute; whorls five, flat, smooth; suture appressed,
very distinct; aperture elongate-triangular; outer lip thin; inner lip callous; lower part of columella
incrusted; columellar plication divided by median groove.
Dimensions. — Long. 12.9 mm.; lat. 5 mm.; body-whorl 9.4 mm.; aperture 7.2 mm.; defl.
40 degrees.
Distinguishable from 0. intorta by double columellar plication, smaller callus,
slenderer form, sharper apex and straighter outer lip; distinguishable from 0. hipli-
cata by slenderer form, smaller size, and more elevated spire.
Common in upper San Pedro series of Los Cerritos; rare in upper and lower
Ban Pedro series, and Pliocene of San Pedro and vicinity. Found also in the
Pleistocene at Spanish Bight and Pacific Beach, San Diego, and at Barlow's ranch,
Ventura.
Living. — Straits of Fuca to San Diego (Cooper).
Pleistocene. — Santa Barbara to San Diego (Cooper): San Pedro; Ventura;
San Diego (Arnold).
Pliocene. — Seven Mile Beach; Twelve Mile House; Kirker's Pass; San Diego
well (Cooper).
Family LV. MARGINELLID.E.
Genus Marginalia Lamarck.
Shell ovately oblong to subcylindrical, smooth, polished, sometimes longitudinally ribbed;
spire short, conical, or concealed; aperture narrow, elongated, obtuse or truncated in fi'ont; columella
plicate; outer lip with a thick marginal varix, its inner margin smooth or crenulated.
Marginella glohella Linn, is a characteristic species.
202. Marginella jewettii Carpenter.
Margi7iella jewetiii Cfk., Proc. Zool. Soc, 1S56, p. 207; Brit. Assn. Rept., 1S63, p. 661. Trvon,
Man. Conch., Vol. V, p. 43, PI. XII, fig. 57, 1883. Cooper, 7th Ann. Rept. Cal. St.
Min., 1888, p. 249. Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part i, 1890, p. 57.
Keep, West Coast Shells, p. 43, fig. 23, 1892. Williamson, Proc. U. S. Nat. Mus.,
Vol. XV, 1892, p. 212, PL XIX, fig. 6.
Shell small, smooth, ovate-oblong; spire barely visible; aperture not extending fijll length
of shell, narrow, elongated, obliquely truncated in front; outer lip thickened with marginal varix,
its inner side smooth; columella with three prominent plications near anterior end, and lesser
ones above.
Dimensions.- — Long. 5 mm.; lat. 3 mm.; aperture 4.7 mm.
Specimens identified by Dr. Dall.
222 CALIFOllNIA ACADEMY OF SCIENCES.
Fouud in the lower San Pedro series at Deadraan Island and San Pedro, and
iu the upper San Pedro series at Crawfish George's, San Pedro, and Deadman Island.
Living. — Monterey to San Pedro (Dall).
Pleistocene. — San Pedro (Cooper; Arnold).
Section Volvarina Hinds.
Shell small, pyriform, polished; spire elevated, but concealed by enamel; aperture not
extending full length of shell; outer lip thin, with incurving flange; columella with sharp plaits.
203. Marginalia (Volvarina) varia Sowerby.
Plate IV, Fuj. 9.
Volvarina varia Sby. , Cpr. , Brit. Assn. Rept., 1863, p. 661. Keep, West Coast Shells, p. 43, 1892.
Shell small, pyriform, smooth; spire elevated slightly, but concealed by enamel of surface;
aperture not extending full length of body- whorl, narrow posteriorly, widening gradually anteriorly;
outer lip thin, with a flange curved inward; columella with four sharp plaits.
Dimensions. — Long. 9 mm.; lat. 5 mm.; aperture 8 mm.
Specimens identified by Dr. Dall.
Found in all of the lower and upper San Pedro series localities in the vicinity
of San Pedro. Found also in the Pleistocene at Twenty-sixth Street, San Diego.
The specimen figured is from the lower San Pedro series at Deadman Island, and is
now in the collection of Delos Arnold.
Living. — Santa Barbara to San Diego (Cooper): Cape St. Lucas; West Indies
(Carpenter).
Pleistocene. — San Pedro; San Diego (Arnold).
Family LVI. MITRID.E.
Genus Mitra Lamarck.
Shell fusiform, thick; spire elevated; aperture small, narrow, notched in front; columella
transversely, somewhat obliquely, plicate; outer lip thick, smooth within, without external varices.
Type, Ultra episcopalis Lam.
204. Mitra maura Swainson.
Mitra niauraSvjhi^., Proc. Zool. Soc, p. 193, 1835. Cpr., Brit. Assn. Rept., 1S63, p. 661. Trvon,
Man. Conch., Vol. IV, p. 121, PI. XXXVI, fig. 67, 1882. Cooper, 7th Ann. Rept.
Cal. St. Min., 1888, p. 257. Keep, West Coast Shells, p. 42, fig. 22, 1892. William-
son, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 211.
Shell mitre-shaped; spire elevated; apex subacute; whorls five or six, only slightly convex,
each appressed against antecedent whorl, forming a distinct suture; surface smooth, except for
incremental lines; aperture long, narrow; outer lip thickened; inner lip not incrusted; columella
with four distinct plaits, which increase in prominence posteriorly.
Dimensions. — Long. 56 mm.; lat. 18.5 mm.; body-whorl 37 mm.; aperture 25 mm.; defl.
30 degrees.
ARNOLD — THE PALEONTOLOGY AND STHATIGRAPHY OF SAN PEDRO. 223
Found in the lower San Pedro series at San Pedro, and in the up[)er San
Pedro series at Deadman Island, San Pedro and Crawfish George's.
Xm?i^.— Farallon Islands to San Diego; South America (Cooper).
Pleistocene. — Santa Barbara to San Diego; San Nicholas Island (Cooper) : San
Pedro (Arnold).
Pliocene. — San Pedro (Arnold).
f
Genus Mitromorpha A. Adams.
Shell small, elongately fusiform; whorls flattened, with revolving lirae, and sometimes longi-
tudinally plicate; aperture narrow; columella straight, slightly transversely Urate; lip acute, smooth
within, scarcely sinuated posteriorly.
Mitromovplia gracilis Carpenter is a characteristic species.
205. Mitromorpha filosa Carpenter.
? Daplmella filosa CpR., Brit. Assn. Rept., 1863, p. 658.
Mitro77iorpha filosa CpR.,* Keep, West Coast vShells, p. 55, 1S92. Williamson, Proc. U. S.
Nat. Mus., Vol. XV, 1892, p. 200, PI. XIX, fig. i.
Shell small, mitre-shaped; apex rounded; whorls six, flat, ornamented with several sharp,
raised, revolving lines; suture impressed, distinct; aperture long, narrow, oblique; outer lip denticu-
late interiorly; inner lip smooth; columella spirally lined externally.
Ditnensions. — Long. 8 mm.; lat. 3.6 mm.; body-whorl 6 mm.; aperture 5 mm.; defl.
55 degrees.
A shell from the Pleistocene shows transverse ridges on first four whorls, but
these become obsolete below this. This transversely ridged specimen is intermediate
between the typical M. filosa and M. intermedia. M. aspera is jirobably the type of
the precursor of the three West Coast species mentioned, then in phylogenetic order
would come M. intermedia, specimens like the ridged variety of J\I. filosa, and lastly
typical M. filosa. The cancellate upper whorls of all the species except M. filosa
show j\J. aspera to be the precursory form.
One specimen in lower San Pedro series of San Pedro.
Living. — Santa Barbara (Carpenter): San Pedro (Simpson).
Pleistocene.- — San Pedro (Arnold).
206. Mitromorpha intermedia, sp. nov.
Plate IV, Fig. 10.
Shell small, mitre-shaped; apex rounded; whorls six; slightly convex; whorls ornamented
with about four equidistant, sharp, raised spiral lines, and numerous rounded, transverse ridges which
are most prominent on angle of whorl; ridges are obsolete, or nearly so, on body-whorl; suture quite
deeply impressed; aperture long, narrow, oblique; outer lip slightly arcuate anteriorly, smooth
interiorly; inner lip smooth; columella spirally lined externally.
Dimcnsio7is. — Long. 9.5 mm.; lat. 3.9 mm.; body-whorl 6.5 mm.; aperture 4.5 mm.; defl.
36 degrees.
224 CALIFORNIA. ACADEMY OF SCIENCES.
This species occuiiies a position nearly midway between M. filoaa and M.
asjiern. It differs from the first in having distinct transverse ridges on the upper
whorls, a smooth inner Jip, a slightly slenderer form, and a more impressed suture;
and differs from the second in having fewer transverse ridges, which are obsolete, or
nearly so, on the body-whorl, a narrower aperture, a slenderer form and more numer-
ous and sharper spiral lines. Pronounced a new variety of Jilosa by Dr. Dall. Its
characteristics would ally it a little more readily with M. aspera, but it has enough
distinctive features to separate it from both.
Rare in lower San Pedro series of Deadraan Island.
Found in the Pleistocene at the bath-house, Santa Barbara. The specimen
figured is the type, which was found in the lower San Pedro series at Deadman
Island, and is now in the United States National Museum.
Xmn^?.— West Coast (?) (Dall).
Pleistocene. — San Pedro; Santa Barbara (Arnold).
Family LVII. FASCIOLARIIDiE
Subfamily FUSING.
Genus Fusus La-march.
Shell fusiform; spire long, acuminate, many-whorled; aperture oval, usually striate within;
outer lip simple; columella smooth; no umbilicus; canal long and straight.
Fusus nicoharicus Lam. is a characteristic species.
207. Fusus barbarensis Trash.
Plate IV, Fig. 15.
Fiisus barbarensis Trask, Proc. Cal. Acad. Sci., Vol. I, 1855, p. 41. Cooper, 7th Ann. Rept. Cal.
St. Min., 1888, p. 240. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 217.
Fitsiis corpukntus (not of Conrad, Wilkes' Expl. Exped., Vol. X, p. 728, PI. XX, fig. 4, 1849)
Cooper, Bull. No. 4, Cal. St. Min. Bureau, Part 3, 1894, p. 26.
Fusus dupetithouarsi {non Kiener), Cooper, Bull. No. 4, Cal. St. Mining Bureau, Part 3, 1894, p. 26.
Shell of medium size, long, slender, fusiform, rather thin; whorls nine, evenly convex, crossed
by about ten rather low, rounded ridges, which fade out toward sutures; body-whorl sometimes lacks
these ridges, but in that case it generally has an irregularly, wavy surface ornamented with numerous
sharp, raised spiral lines with sometimes smaller lines intercalated; suture deeply appressed; aperture
subelliptical; outer lip thin, smooth margin, with prominent, internal spiral lines beginning just pos-
terior to margin; inner lip incrusted, sometimes not covering the spiral sculpture of columella;
columella long, nearly straight, except for curve backwards, spirally ridged; canal long, narrow,
nearly straight.
Dimensions. — Long. 60 mm.; lat. 20 mm.; body-whorl 39 mm.; aperture, including canal,
31 mm.; canal 15 mm.; defl. 32 degrees.
Distinguishable from F. rohustus and F. rugosus by much slenderer form, longer
spire, more clear-cut spiral lines, and longer and straighter canal. This is the oldest
AKlSfOLD — THE PALEONTOLOGY AND STllATIGKAPHY OF SAN PEDRO. 225
form found in this locality. There is no doubt about the close relationship of the
three species, barbarensis, robustus and rugosus, as the large series of each which the
writer has had during the preparation of this paper shows forms nearly, if not quite,
filling the gaps between the three types. JF'. barbarensis is probably the precursor
of the other two forms, and although it occurs in the later horizons in which the
other two sjiecies are the denominating types, still, judging by numbers, this form
reached its maximum development in the upper San Pedro series.
Specimens identified by Dr. Dall.
Common in the Pliocene, rare in the lower San Pedro series of Deadman
Island; one or two specimens found at each of Deadman Island, San Pedro, and
Crawfish George's in the upper San Pedro series. The specimen figured is from the
Pliocene at Deadman Island, and is now in the collection of Delos Arnold. This
and several other species have been reported from the "Miocene of Deadman
Island." Although the lowest horizon at Deadman Island is Miocene, still all of the
fossils reported as occurring in the Miocene at that place come out of a Pliocene
stratum which rests unconformably upon the Miocene.
Living — San Pedro (Oldroyd; Raymond).
Pleistocene. — Santa Barbara (Trask; Cooper): San Pedro (Arnold).
Pliocene — San Pedro (Arnold).
208. Fusus luteopictus Ball.
Fiisi/s /ufeoprdus Dall, " ' Proc. Cal. Acad. Sci.,' 1877, p. 4." (Author's unauthorized reprint,
issued March ig, 1877.)
Fiisics ambustus Gld., Cpr., Brit. Assn. Rapt., 1863, p. 664 (pars.); (not of Gould) {fide Dall.)
Fusus genicnlus CoNR., Gabb, Pal. Cal., Vol. II, p. 71, 1S69 (pars. syn. exel.) (7?^,? Dall).
Fusus avibustus (^LV).,(ZoovEK, Cal. Monterey Shells, Am. Jour. Conch., Vol. VI, p. 70; Geog.
Cat., No. 787 (most Californian writers) {fide Dall).
Fusus lulcopichis Dall, Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1S92, p. 217, PI. XX, fig. i.
Shell small, fusiform; whorls five, convex, crossed by nine rounded ridges which reach their
maximum development on the middle of whorl; surface ornamented with three or four prominent
spiral lines, with finer ones sometimes intercalated; suture appressed; aperture subovate; outer lip
not thickened, with internal spiral lines; inner lip incrusted; columella short; canal very short, narrow.
Dimeyisions. — Long. 19 mm.; lat. 10 mm.; body-whorl 13.5 mm.; aperture, including canal,
10 mm.; canal 3 mm.; defl. 38 degrees.
Distinguishable by small size and very short canal.
Rare in the lower San Pedro series at Deadman Island; common in the upper
San Pedro series at Crawfish George's, but rare in the same horizon at San Pedro,
Deadman Island and Los Cerritos. Most of the specimens obtained came from
Crawfish George's.
Living. — Farallon Islands to San Diego (Dall).
Pleistocene. — San Pedro (Arnold).
(29) March 19, 1903.
226 CALIFORNIA ACADEMY OF SCIENCES.
209. Fusus robustus Trask.
Fusus robustus Trask, Proc. Cal. Acad. Sci., Vol. I, 1855, p. 41. Cooper, 7th Ann. Rept. Cal. St.
Min., 1888, p. 241.
Fusus kobelli {noi of Dall), of Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 240 (in part).
Shell of medium size, elongate-fusiform, thick; whorls about si.\, convex, crossed by eight
or nine prominent rounded ridges which are most prominent on angle of whorl (these ridges are
sometimes obsolete on the anterior part of the body-whorl); spiral sculpture consists of four to six
prominent raised lines, with sometimes smaller lines intercalated; suture appressed, deep, distinct;
aperture pyriform; outer lip smooth on inner edge, but with numerous spiral ridges further in; inner
lip smooth; columella spirally ridged externally; canal rather short, narrow.
Dimensiotis. — Long. 34 mm.; lat. 14 mm.; body-whorl 22.5 mm.; aperture, including canal,
17 mm.; canal 5 mm.; defl. 40 degrees.
Distinguishable from F. rugosas by smaller size, heavier shell, lack of promi-
nent angular appearance of whorls and ridges near posterior suture, less number of
wliorls and relatively shorter canal. Upon examining a large series of this species
and of F. rugosus the writer has no hesitancy in separating these two forms of Trask's.
Distinguishable from F. kohdti by deeper ap^^ressed suture, stronger, revolving ridges,
narrower form, and lack of wavy sutural band on posterior edge of whorl. F. robustus
is probably a precursor of F. kohelti. This species has been identified as F. amhustus
by many West Coast conchologists, including Cooper and perhaps Carpenter. Speci-
mens identified by Dr. Dall.
Found only in the upper San Pedro series; rather common at Old San Pedro.
Found also in the Pleistocene at the bath-house, Santa Barbara.
Living. — Santa Barbara to San Diego (California State Museum).
Pleistocene. — Santa Barbara (Cooper; Arnold): San Pedro (Trask; Arnold).
210. Fusus rugosus Trask.
Plate IV, Fig. 7.
Fusus rugos/is Trask, Proc. Cal. Acad. Sci., Vol. I, 1855, p 41. Cooper, 7th Ann. Rept. Cal. St.
Min., 1888, p. 241.
Shell of medium size, elongate, fusiform, thin; whorls eight, convex, crossed by eight to
eleven rounded ridges, which rise to greatest prominence on upper side of whorl; body-whorl ventri-
cose and sometimes lacking transverse ridges on forward part; surface ornamented with several
prominent raised lines, with fine lines sometimes intercalated; suture deeply appressed, wavy;
aperture elliptical; outer lip thin, with interior spiral ridges extending nearly to rim; inner lip smooth;
columella long, slightly twisted, spirally ridged; canal long, narrow, slightly curved.
Dimensions. — Long. 50 mm.; lat. 19 mm.; body-whorl 35 mm.; aperture, including canal,
28 mm.; canal 13 mm.; defl. 44 degrees.
The specimen described and figured is a small one. Some of the specimens
are over 65 mm. in length.
Distinguishable from F. robustus by larger size, thinner shell, longer canal,
more ventricose body-whorl, and greater development of transverse ridges on ujiper
portion of whorl. Perhaps F. rugosus is the precursoi- of F. robustus. If so, then
ARNOLD — THE PALEONTOLOGY AND STKATIGEAPHY OF SAN PEDEO. 227
rohustus is a degenerate form in so far as size and beauty go, for rugosus is truly a
magnificent shell, while the former is small and much less attractive. This species
has been identified as F. amhiistus, and is so labeled in the State Museum collection
at Berkeley. F. nmbusfus of Gould is a slenderer, longer pillared form from Central
America.
Found only in the lower San Pedro series of Deadman Island. The shells in
this horizon are beautifully preserved, this form especially being nearly always found
in a perfect condition, and having a shell that in most cases is translucent. Rather
rare. The specimen figured is from the lower San Pedro series at Deadman Island,
and is now in the collection of Delos Arnold.
Living.—Santa Barbara to San Diego (California State Museum).
Pleistocene.— Santa Barbara (Cooper): San Pedro (Arnold; Trask).
Genus Pisania Bivona.
Shell oblong; spire prominent; whorls smooth or spirally striated; canal very short; outer
lip thickened and crenated.
Pisania pusio Linn, is a characteristic species.
211. Pisania fortis Carpenter.
Pisania foriis Cpr., Ann. & Mag. Nat. Hist., 3rd Sen, Vol. XVII, 1866, p. 277. Cooper, 7th Ann.
Rept. Cal. St. Min.. 18S8, p. 260.
Shell fusiform, short; spire elevated; apex subacute; whorls five or six, convex on upper
whorls to angular on body-whorls; eight wave-like ribs, most prominent on the angle of the whorl;
prominent sutural riblet on posterior margin of whorl; surface ornamented with three to five promi-
nent, squarish, rough, revolving ridges, between which are finer raised lines; suture wavy, appressed,
distinct; aperture pyriform; outer lip denticulated; umbilicus subperforate.
Dimensio7is. — Long. 49 mm.; lat. 29 mm.; body-whorl 38 mm.; aperture 25 mm.; defl.
58 degrees.
This species resembles some specimens of Purpura crispata, but is a lighter
shell, and the sculpture is entirely different. Originally described from a specimen
from the Pleistocene of Santa Barbara. It has never been found living.
Rare in the upper San Pedro series of San Pedro and Deadman Island; two
specimens found. Found in the Pleistocene at Pacific Beach, San Diego.
Pleistocene. — Santa Barbara (Cooper): San Pedro; San Diego (Arnold).
Family LVIII. BUCCINID^.
Genus Chrysodomus Sivainson.
Shell fusiform, ventricose; spire elevated; whorls rounded; covered with a horny epidermis;
apex papillary; aperture oval; canal short; inner lip simple, smooth.
Chrysodomus antiqua Linn, is a characteristic species.
228 CALIFORNIA ACADEMY OF SCIENCES.
212. Chrysodomus rectirostris Carpenter.
Plate VII, Fig. 7.
Chrysodomus rectirostris Qvv.., Brit. Assn. Rept., 1863, p. 664; Proc. Phil. Acad. Nat. Sci., 1865,
p. 64. Tryon, Man. Conch., Vol. II, p. 131, PL LIII, fig. 348, 1881.
Shell small, turreted, slender; apex acute; whorls nine or ten, slightly conve.x, with about
fourteen rounded, transverse ridges reaching from suture to suture; ridges follow direction of lines of
growth, which are convex anteriorly; spiral sculpture consists of numerous fine furrows; suture
impressed, distinct; body-whorl slightly angulated at base; aperture elliptical; outer lip thin, bulging
above canal; inner lip smooth, incrusted; columella long, straight, narrow, smooth on inner part;
canal long, straight, narrow.
Dimensio7is. — Long. 28 mm.; lat. 7 mm.; body-whorl 14.5 mm.; aperture, including canal,
1 1.5 mm.; canal 5 mm.; defl. 22 degrees.
This species looks something like a Pleurotoma, but may be distinguished by
the straight canal and almost flat whorls. Carpenter's description in the British
Association Report for 1863 is misleading. In describing this species he says the
shell is "small, white, smooth, with straight canal." Why he uses "smooth" in
describing such a decidedly sculptured form is not easy to understand. Sevei'al
specimens of this species were identified from Carpenter's type by Dr. Dall.
Rare in the Pliocene and lower San Pedro series at Deadman Island, and in
the upper San Pedro series at Crawfish George's. The specimen figured is from the
lower San Pedro series at Deadman Island, and is now in the collection of Delos
Arnold.
Living. — Puget Sound (Carpenter).
Pleistocene. — San Pedro (Arnold).
213. Chrysodomus tabulatus Baird.
Plate VII, Fig. 0.
Chrysodomus tabulatus Baird, Proc. Zool. Soc, 1863, p. 66. Cpr., Brit. Assn. Rept., 1863, p. 663;
Nat. in British Columbia, Vol. II, p. 356. Cooper, 7th Ann. Rept. Cal. St. Min.,
1888, p. 235.
Neptwiea tabulaia "Qmrd, GAYiv,, Pal. Cal., Vol. II, p. 71, 1869. Tryon, Man. Conch. , Vol. II,
p. 121, PL XLIX, fig. 286, 1881.
Shell large, fusiform; spire elevated; apex subacute; whorls eight, sharply angulated and
keeled above, forming a rimmed, spiral table; surface ornamented with revolving ridges of alternating
size; suture very deeply impressed; aperture pyriform; outer lip thin, smooth; inner lip incrusted;
canal long, narrow, curved backwards; columella twisted, spirally ridged.
Dimensions. — Long. 80 mm.; lat. 34 mm.; body-whorl 55 mm.; aperture, including canal,
42 mm.; canal 19 mm.; defl. 44 degrees.
Rather common in Pliocene; rare in lower San Pedro series of Deadman
Island and San Pedro. Found also in the Pleintocene at the bluflf west of the bath-
bouse, Santa Barbara, and at the old irrigating ditch north of Ventura. The
AKNOLD — THE PALEONTOLOGY AND STRATIGKAPHY OF SAN PEDKO. 229
specimen figured was from the Pliocene, Deadman Island, and is now in the collec-
tion of Delos Arnold.
Living. — Straits of Fuca to Catalina Island (Cooper).
Pleistocene.— &iin Pedro; Santa Barbara; Ventura (Arnold).
Pliocene. — Eagle Prairie; Twelve Mile House; San Fernando; Santa Barbara
(Cooper); San Pedro (Cooper; Arnold).
214. Chrysodomus, sp. indet.
Two poorly preserved, undeterminable species; both fusiform, one with rounded
whoi'ls, the other slightly tabulated on upper part; fine spiral sculpture on both.
These specimens have the shape of C. dims. They correspond quite closely to the
descriptions of some of tlie living species which now inhabit boreal waters.
Found in the Pliocene of Deadman Island.
Pliocene. — San Pedro (Arnold).
Genus Siphonalia A. Adams.
Shell ovately fusiform, sometimes variegated in coloring; rather thin; epidermis very thin,
fugacious; last whorl ventricose, shouldered, usually nodosely plicate and spirally ribbed; aperture
oval; outer lip thin; columella smooth; canal rather short, twisted.
Siphonalia nodosa Mart, is a characteristic species.
215. Siphonalia kellettii Forbes.
Plate IV, Fig. 5.
Siphonalia kellettii ¥o^hKS, Proc. Zool. Sec, 1850, p. 274, Pi. X, fig. 10. Cpr., Brit. Assn. Rept.,
1863, p. 663. Tryon, Man. Conch., Vol. Ill, p. 134, PL LIV, fig. 352. Cooper, 7th
Ann. Rept. Cal. St. Min., 1888, p. 264. Dall, Trans. Wagner Inst. Sci., Vol. Ill,
Part. I, 1890, p. 122. Keep, West Coast Shells, p. 22, 1S92.
Shell large, fusiform; spire elevated; apex subacute; whorls seven or eight, angulated
anterior to middle with eight to ten prominent nodes on angle; concave near posterior margin,
where it is appressed against the antecedent whorl; numerous fine, deep grooves furnish the spiral
ornamentation; suture appressed, wavy; aperture ovate; outer lip not thickened; inner lip incrusted;
columella twisted; umbilicus subperforate; canal long, narrow, curved back.
Dimensions. — Long. 114 mm.; lat. 59 mm.; body-whorl 80 mm.; aperture 37 mm.; canal
22 mm.; defl. 44 degrees.
Often brought up alive in the nets of fishermen at San Pedro, but rarely found
fossil. Found in the upper San Pedro series at San Pedro, Los Cerritos, and Crawfish
George's. Found also in the Pleistocene at Pacific Beach, San Diego. The speci-
men figured was obtained in the upper San Pedro series at San Pedro, and is now in
the private collection of Delos Arnold.
Living. — Santa Barbara to San Diego; Japan (Cooper).
230 • CALIFORNIA ACADEMY OF SCIENCES.
Pleistocene. — San Pedro to Sau Diego (Cooper) : Sau Pedro; Sail Diego
(Arnold).
Genus Macron //. <£■ A. Adams.
Shell ovate, solid, with a thick epidermis; spire elevated; columella wrinkled, with a callosity
at the upper part; outer lip thin, with a small tooth anteriorly.
Type, Macron kelkttii A. Ads.
216. Macron kellettii A. Adams.
Pscudoliva kellettii A. Ad., Proc. Zool. Soc, 1853, p. 185.
Macron kellettii h. Ad., Cpr., Brit. Assn. Rept., 1863, p. 664. Tryon, Man. Conch., Vol. Ill,
p. 214, PI. LXXXII, fig. 477, 1881. Keep, West Coast Shells, p. 21, 1892. Cooper,
Bull. No. 4, Cal. St. Min. Bureau, Part 3, 1894, p. 27.
Shell ovate, solid, subperforate; spire prominent; whorls rounded; suture canal-like; last
whorl spirally sulcated; aperture oval; columella callous posteriorly, anterior portion produced and
flexed; posterior part of lip bent, anterior part dentate. Canal a mere notch. Average length
about 25 mm.
One specimen in upper San Pedro series of San Pedro.
Living. — Lower California (Keep): Catalina Island to Lower California
(Cooper).
Pleistocene. — San Pedro (Arnold) : San Joaquin Bay, Orange County (Bowers).
Pliocene. — Ventura County (Bowers).
217. Macron lividus A. Adams.
Macron lividus A. Ad., Cpr., Brit. Assn. Rept.. 1863, p. 664. Keep, West Coast Shells, p. 20,
fig. 2, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 216.
Shell small, ovate, solid; spire elevated; apex subacute; whorls five, evenly convex, smooth;
suture distinct; aperture ovate; outer lip sharp and curved; inner lip short and bent; columella with
a strong fold near the top of the aperture.
Dimensions. — Long. 19 mm.; lat. 10 mm.; body-whorl 14 mm.; aperture 10 mm.
This species is characterized by its smooth surface and small size. One
specimen found in the upper San Pedro series at the lumber yard, San Pedro.
Living. — San Pedro (Williamson) : San Diego to Lower California (Carpenter).
Pleistocene. — San Pedro (Arnold).
Family LIX. NASSID^E.
Genus Nassa Lamarck.
Shell ovate, ventricose; body- whorl variously sculptured; aperture ovate, with a short, reflected,
truncated, anterior canal; inner lip smooth; often widely spread over with enamel, with a posterior
callosity or a blunt dentiform; outer lip dentated, internally crenulated.
Nassa mutahilis Linn, is a characteristic species.
ARNOLD — THE PALEONTOLOGY AND STKATIGKAPHY OF SAN PEDUO. 231
2i8. Nassa californiana Conrad.
Plate IV, Fig. 3.
Schizopyga calif orjiiana Con., Proc. Phil. Acad. Nat. Sci., 1856, p. 315; Pac. R. R. Rept., Vol. VI
p. 69, PL II, fig. I, 1857.
Schizopyga californica CoN., Tryon, Man. Conch., Vol. IV, p. 55, PI. Ill, fig. 32, 1882.
Nassa californiana Con., Dall, Proc. U. S. Nat. Mus., Vol. XIV, 1891, p. 177. Cooper, Bull.
No. 9, Cal. St. Min. Bureau, Part 3, 1894, p. 29.
Nassa fossata van, Gabb, Pal. Cal., Vol. II, pp. 47, 74, 1869.
Shell large, conical; whorls seven, convex, ornamented with about thirteen prominent,
rounded, posteriorly sloping, transverse ribs and four or five' slightly less prominent sharp, revolving
ridges; the transverse ridges tend to become less prominent on the anterior part of the body-whorl;
suture deeply impressed, distinct; aperture subovate; outer lip thin and denticulated by ends of
internal revolving ridges; inner lip slightly incrusted; columella short, twisted, spirally and longitudi-
nally ornamented, and deeply grooved next to body-whorl; anterior sinus very short, broad, recurved.
Dimensions.- — Long. 37 mm.; lat. 20.5 mm.; body-whorl 24 mm.; aperture 16.5 mm.; defl
48 degrees.
The most beautiful and one of the hirgest of the Pleistocene Nassau. Easily-
distinguishable by the ornamentation and size.
Rare in the upper San Pedro series, except at one place in the bluf! just
north of the town of San Pedro, where quite a few very fine specimens have been
found; also found in the Pliocene and lower San Pedro series at Deadman Island;
and in the upper San Pedro series at Los Cerritos, Deadman Island, and Long Beach.
Found also in the Pleistocene at Barlow's ranch, Ventura; and at Pacific Beach,
San Diego. The specimen figured is from the upper San Pedro series of San Pedro;
and is now in the private collection of Delos Arnold.
Living. — Drake's Bay to Cedros Island, Lower California (Cooper).
Pleistocene. — San Pedro; Ventura; San Diego (Arnold).
Pliocene. — San Pedro (Arnold).
Miocene. — Santa Clara County (Cooper).
219. Nassa cerritensis, sp. nov.
Pl.\te IV, Fig. 1.
Shell small, conical; spire elevated; apex subacute; whorls eight, slightly convex, crossed
by seven to ten prominent, rounded ridges which are less prominent near the suture; spiral sculp-
ture consists of nine to eleven sharp, raised lines; three upper whorls have a cancellate appearance;
suture appressed, wavy; aperture ovate; outer lip thickened by denticulated ridge on inner side;
inner lip smooth, incrusted, the incrustation completely covering the spiral sculpture internally;
columella twisted, spirally sculptured, with deep groove next to body-whorl; canal short, broad,
recurved.
Dimensions. — Long. 30 mm.; lat. 14.5 mm.; body-whorl 18 mm.; aperture 11 mm.; defl.
30 degrees.
This species varies ranch, especially in deflection and in tlie number of trans-
verse ridges. The deflection of the upper whorls is sometimes as high as 60 degrees,
232 CALIFOllNIA ACADEMY OF SCIENCES.
while that of the lower whorls would be about one-half of that. Home of the adult
shells also show a deflection of 50 degrees. The robust shells as a rule show more
transverse ridges than the slenderer forms. Distinguishable from var. cooperi by
less angulated whorls and ridges, less impressed suture, greater deflection of upper
whorls, and larger size. The robust form somewhat resembles N. californiana, but
is distinguishable from that species by its appressed, rather than impressed suture,
less prominence of spiral lines, and smaller size. Dr. Dall pronounces this species a
precursor of JSF. coojjeii.
Rather common at Los Cerritos, where the type was found. One or two
specimens found in the upper San Pedro series at San Pedro, Long Beach, and
Crawfish George's. Found also in the Pleistocene at Spanish Bight, San Diego.
The specimen figured is the type, which came from the upper San Pedro series at
Los Cerritos, and is now in the United States National Museum.
Pleistocene. — San Pedro; San Diego (Arnold).
220. Nassa fossata Gould.
Buccinum fossaiuvi Gld. , Proc. Bost. Soc. Nat. Hist., 1850, p. 152. Otia, Conch., p. 67, 1862.
Nassa fossata Gld., H. & A. Adams, Gen. Rec. Mollusca. Cpr., Brit. Assn. Rept., 1863, p. 662.
Gabb, Pal. Cal., Vol. II, p. 74, 1S69. Tryon, Man. Conch., Vol. IV, p. 55, PI. XVII,
figs. 316, 318, 1882. Cooper, 7th Ann. Rept. Cal. St. Min., 18S8, p. 253. Keep,
West Coast Shells, p. 36, fig. 16, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV,
1892, p. 212.
Shell small, conical; spire elevated; apex subacute; whorls seven, convex; body-whorl
ventricose; ornamentation of fourth and fifth whorl consists of five or si.x strong, nodose, spiral
ridges which increase in number by intercalation on the lower whorls; the prominence of the nodes
varies inversely with the number of ridges, the ridges on the body-whorl being nearly smooth and
alternating large and small; the ridges near the angle of the whorl reach the greatest prominence;
suture deeply impressed, distinct; aperture ovate; outer lip thickened and denticulated by ends of
revolving internal ridges; inner lip incrusted, the incrustation spreading over part of body-whorl and
columella; columella short, curved, spirally striated, and grooved deeply next to body-whorl; anterior
sinus short, broad, recurved.
Dimejisions. — Long. 29 mm.; lat. 17 mm.; body-whorl 21 mm.; aperture, including canal,
14.5 mm.; defl. 50 degrees.
The adolescent shell of this species resembles iV^. ferpinguis,, but may be
distinguished by the greater convexity of the body-whorl, greater deflection, and
general more solid appearance. The adult shells are characterized by their general
solid appearance, great deflection, and the great difference in sculpture between the
upper and lower whorls.
Found in the Pliocene at Deadman Island; in the lower San Pedro series at
Deadman Island and San Pedro, and in the upper San Pedro series at all of the
localities in the vicinity of San Pedro. Found also in Pleistocene at Spanish Bight
and Pacific Beach, San Diego; and at old irrigating ditcli and Barlow's ranch.
ARNOLB — THE PALEONTOLOGY AND STEATIGEAPHY OF SAN PEDRO. 233
Ventura. The specimens of this species found at Crawfish George's are character-
ized by their large size and elevated spire, with deeply impressed suture.
Living. — Straits of Fuca to San Diego (Cooper).
Pleistocene. — Santa Barbara to San Diego (Cooper): San Pedro; Ventura;
San Diego (Arnold).
Pliocene. — Danger Creek; Santa Rosa; Soquel, Santa Cruz County; San Diego
well (Cooper): San Pedro (Arnold).
Miocene. — Martinez; Walnut Creek; Griswold's, San Benito County; Foxin's,
Santa Barbara County (Cooper).
221. Nassa insculpta Carpenter.
Nassa insculpta Cpr., Brit. Assn. Rept., 1863, p. 662; Proc. Cal. Acad. Sci., Vol. Ill, 1866, p. 223.
Tryon, Man. Conch., Vol. IV, p. 38, PI. XII, fig. 154, 1882; (not of Cooper, ytli Ann.
Rept. Cal. St. Min., 1S88, p. 253). Williamson, Proc. U. S. Nat. Mus., Vol. XV,
1892, p. 2X2, PI. XXIII, fig. 6.
Shell small, conical; spire elevated; apex subacute; whorls seven, nearly flat, but obliquely
truncated near margin; sculpture consists of numerous fine, spiral furrows, which are most promi-
nent on lower portion of body-whorl; four upper whorls have prominent transverse ridges; aperture
subquadrate; outer lip thickened by a slightly denticulated ridge; inner lip incrusted slightly, but
spiral ornamentation shows through the incrustation; columella short and separated from body-whorl
by deep, narrow groove; canal short, broad, curved.
Dimensions. — Long. 20 mm.; lat. 11 mm.; body-whorl 12.8 mm.; aperture, including canal,
9 mm.; defl. 38 degrees.
Distinguishable by lack of any but spiral ornamentation on lower whorls. A
specimen in the State Museum collection at Berkeley labeled N . insculpta is not the
species, but is close to JSf. versicolor var. hooveri. This is probably the specimen upon
which Cooper bases his report of the occurrence of A^. insculpta at Santa Barbara.
Bare in upj)er San Pedro series of San Pedro; one specimen.
Living. — Catalina Island (Cooper; Raymond).
Pleistocene. — San Pedro (Williamson; Arnold).
222. Nassa mendica Gould.
Nassa mendica Gld., Proc. Bost. Soc. Nat. Hist., 1850, p. 155. Wilkes' E.xpl. Exped., Vol. XII,
p. 263, PI. XIX, fig. 331, 1852. Otia, Conch., p. 70, 1862. Cpr., Brit. Assn. Rept.,
1863, p. 662; ^=M. woodwardi Fbs.; =A^. gibbsii Cooper {Jide Tryon, Man. Conch.,
Vol. IV, p. 56, PI. XVII, figs. 320-323, 1882). Gabb, Pal. Cal., Vol. II, p. 74, 1869.
Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 253. Keep, West Coast Shells, p. 37,
1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 213.
Shell small, conical; spire elevated; apex acute; whorls seven, convex; ornamented with a
varying number of transverse ridges and a few less prominent spiral ridges; suture deeply impressed,
distinct; aperture subquadrate; outer lip thin, smooth on edge, but denticulated remote from margin;
inner lip incrusted; columella curved, spirally striated, and separated from body-whorl by deep
groove; canal short, recurved.
Dimensions. — Long. 18.5 mm.; lat. 8 mm.; body- whorl 11 mm.; aperture, including canal,
7.5 mm.; defl. 38 degrees.
( 30 ) March 20, 1903.
234 CALIFORNIA ACADEMY OF SCIENCES.
A species varying principally in the number and prominence of transverse
ridges. Distinguishable from N. perpinguis by acuteness of spire.
Found in all of the fossiliferous formations at all of the localities in the vicinity
of San Pedro. N. mendica is much rarer than the variety cooperi. Found in the
Pleistocene at the bath-house, Santa Barbara; at Barlow's ranch, and the old irri-
gating ditch, Ventura; and at Spanish Bight and Pacific Beach, San Diego.
Living. — Sitka to San Diego (Cooper).
Pleistocene. — Santa Barbara to San Diego (Cooper): San Pedro; Santa
Barbara; Ventura; San Diego (Arnold).
Pliocene. — Kirker's Pass; Twelve Mile House, San Mateo County; San
Diego well (Cooper): San Pedro (Arnold).
223. Nassa mendica Gould, var. cooperi Forbes.
Nassa cooperi Fbs. , Froc. Zool. Soc, 1850, p. 273, PI. XI, fig. 4. Cpr., Brit. Assn. Rept, 1863,
p. 662. Gabb, Pal. Cal., Vol. II, p. 74, 1869. Cooper, 7th Ann. Rept. Cal. St. Min.,
18S8, p. 253. Keep, West Coast Shells, p. 37, fig. 18, 1892.
JVassa metidica var. cooperi Fbs., Tryon, Man. Conch., Vol. IV, p. 56, PI. XVII, figs. 322,323,
1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 213.
Shell like A/', mendica, except that the transverse ridges are more prominent and less
numerous. Mutations occur between the extreme N. mendica with latticed ornamentation consisting
of equally prominent spiral and transverse ridges, and the extreme N. cooperi with only six large,
transverse ribs.
More common than the typical N. mendica. Found in the lower and upper
San Pedro series and Pliocene of the San Pedro region. Found in the Plei.stocene
at Pacific Beach, San Diego.
Living. — Sitka to San Diego (Cooper): Catalina Island (Stearns).
Pleistocene — Santa Barbara to San Diego (Cooper): San Pedro; San Diego
(Stearns; Arnold).
Pliocene. — Kirker's Pass; Twelve-mile House, San Mateo County; San
Diego well (Cooper): San Pedro (Arnold).
224. Nassa perpinguis Hinds.
Nassa perpinguis Hds., Voyage Sulphur, p. 36, PL IX, figs. 12, 13, 1844. Cpr., Brit. Assn. Rept.,
1863, p. 662; Gabb, Pal. Cal., Vol. II, pp. 47, 75, 1869. Tryon, Man. Conch., Vol. IV,
p. 56, PI. XVII, fig. 319, 1882. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 253.
Keep, West Coast Shells, p. 38, fig. 19, 1892. Williamson, Proc. U. S. Nat. Mus.,
Vol. XV, 1892, p. 213.
Nassa inierstriaia, Con., Pac. R. R. Rept, Vol. V, p. 327, PI. VI, fig. 49, 1856.
Shell small, conical; spire elevated; apex subacute; whorls seven, convex, abruptly truncated
at posterior margin, forming a spiral table; ornamentation consists of sharp, spiral ridges with
slightly wider interspaces, and posteriorly sloping transverse ridges, the whole giving a decidedl)'
cancellate appearance to the surface; suture deeply impressed, distinct; aperture subovate; inner
ARNOLD — THE PALEONTOLOGY AND STKATIGRAPHY OF SAN PEDRO. 235
portion of aperture ridged by spiral sculpture; outer lip thin; inner lip thinly incrusted; columella
twisted and spirally ornamented; groove on upper part of columella prominent; canal short, curved.
Dijnensions. — Long. 23 mm.; lat. 12.3 mm.; body-whorl 15 mm.; aperture, including canal,
II mm.; defl. 40 degrees.
The transverse ornamentation is the most prominent in the upper whorls,
while in the later ones the spiral ridges are the most important. On the body-whorl
the tranverse ridges sometimes become nearly obsolete, being represented only by
lines of growth.
Common in the upper and rare in the lower San Pedro series at San Pedro
and vicinity. Also found in the Pliocene at Deadman Island and Timm's Point.
Found in the Pleistocene at Spanish Bight and Pacific Beach, San Diego; and at the
old irrigating ditch and Barlow's ranch, Ventura.
Living. — San Francisco to San Diego; Lower California (Cooper).
Pleistocene. — Santa Barbara to San Diego (Cooper): San Pedro; Ventura;
San Diego (Arnold).
Pliocene. — San Diego well (Dall): San Pedro (Arnold).
Miocene. — Santa Monica and Aliso Creek, Los Angeles County (Cooper).
225. Nassa tegula Reeve.
Nassa tegula Rye., Icon. Conch., Nassa, No. 98, PI. XV, 1853. Cpr., Brit. Assn. Rept., 1863,
p. 662. Gabb, Pal. Cal., Vol. II, p. 74, 1869. Tryon, Man. Conch., Vol. IV, p. 39,
PI. XIII, figs. 166, 167, 1882. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 253.
Keep, West Coast Shells, p. 37, fig. 17, 1892. Dall, Proc. U. S. Nat. Mus., Vol. XV,
1892, p. 213.
Shell small, conical; spire elevated; apex subacute; whorls five, slightly angulated at middle,
with nine or ten prominent transverse ridges most prominent on angular part of whorl; these ridges
are sometimes divided by spiral grooves into two or more nodes; suture impressed, distinct; aper-
ture subquadrate; outer lip thickened by a row of elongated denticles; inner lip smooth and incrusted,
the incrustation spreading over the columella and the front of the shell like an apron; a rather shallow
groove separates the lower portion of columella from body-whorl; canal very short.
• Dimensions. — Long. 11 mm.; lat. 7 mm.; body-whorl 7.9 mm.; aperture, including canal,
5 mm.; defl. 58 degrees.
The most robust of the Naa&as, found in this locality. Distinguishable by
the prominence of the incrustation on the inner lip. Dr. Dall says that this species
is close to jV. vihex of the Atlantic coast.
Rare in the upper San Pedro series at San Pedro, Los Cerritos, Long Beach,
Deadman Island, and Crawfish George's; also occasionally found in the lower San
Pedro series at Deadman Island and San Pedro. Found also in the Pleistocene at
Twenty-sixth Street and Spanish Bight, San Diego.
Living. — Santa Barbara to San Diego; Lower California (Cooper).
Pleistocene. — Santa Barbara to San Diego (Cooper): San Pedro; San Diego
(Arnold),
236 CALIFOKNIA ACADEMY OF SCIENCES.
226. Nassa versicolor C. B. Adams, var. hooveri, var. iiov.
Plate IV, Fig. 6.
Nassa versicolor C. B. Ad., Panama Cat., p. 66, 1852. Tryon, Man. Conch., Vol. IV, p. 50, PI. XV,
figs. 270-272, 275, 1882.
Shell small, conical; spire not highly elevated; apex subacute; whorls six, slightly convex,
crossed by fifteen prominent rounded ribs which bend slightly forward on the upper whorls, and are
abrupdy truncated at the sutures; on the body-whorl these ribs are concave anteriorly and become
obsolete on the lower portion of the whorl; ribs on the upper whorls are of uniform size for their full
length; suture deeply impressed, distinct; spiral ornamentation consists of eleven to thirteen grooves,
which extend to base on body-whorl; columella extended, plication on inner side, and deep, narrow
groove around it at base of body-whorl; outer lip thickened by a prominent, smooth ridge on the
inner side; inner lip incrusted, the spiral sculpture, however, showing through the incrustation;
canal short, broad, with effuse lips.
Dimensiots. — Long. 14.5 mm.; lat. 9 mm.; body-whorl 10 mm.; aperture, including canal,
7 mm. ; defl. 54 degrees.
A unique form for this locality; somewhat resembles N. tegula in shape, but
easily distinguishable from that species by the sculpture. Pronounced a variety of
]Sr. versicolor Adams, by Dr. Dall. N. versicolor is found in the southern fauna, its
habitat being Panama to Mazatlan according to Tryon.
Hare in upper San Pedro series of San Pedro; two specimens found, one a
junior. The specimen figured is the type, which was obtained from the upper San
Pedro series of San Pedro, and is now in the United States National Museum.
Pleistocene. — San Pedro (Arnold).
Family LX. COLUMBELLIDiE.
Genus Colvimbella Lamarck.
Shell strombiform or obovate, smooth or longitudinally or tranversely ribbed; internal lip
excavated in the middle, crenulated or denticulated; outer lip inflected and internally thickened and
crenulated in the middle.
Columbella mercatoria Lam. is a characteristic sjiecies.
227. Columbella solidula Reeve, var. praecursor, var. nov.
Plate X, Fig. 4.
Columbella solidula RvE., Conch. Icon., Vol. XI, PI. XXIV, fig. 149, 1859. Tryon, Man. Conch.,
Vol. V, p. 147, PI. LII, figs. 92 and 93, 1883.
Shell small, broadly fusiform; spire elevated; apex rounded; whorls seven, only slightly
convex, slightly shouldered above, smooth; body-whorl two-thirds length of shell, with row of nodes
on shoulder, each node being the termination of a faint transverse ridge which becomes obsolete on
lower portion of whorl; columella with spiral sulcations on exterior; aperture rhomboidal, narrow;
outer lip thickened internally by row of prominent teeth; inner lip smooth; canal short, recurved.
Dimensions. — Long. 14.5 mm.; lat. 6.5 mm.; body-whorl 10 mm.; aperture, including
canal, 7.5 mm.; canal i mm.; defl. 42 degrees.
ARNOLD — THE PALEONTOLOGY AND STRATIGEAPHY OF SAN PEDKO. 237
This unique species is distinguishable by its smooth upper whorls, and sculp-
tured body-whorl. Pronounced a variety of C. solidula Rve. by Dr. Dall.
The shell of which this form is a variety is found living on the coast of Ecua-
dor, South America. The type is the only specimen that has been found in the
upper San Pedro series at San Pedro; it is figured, and is now in the United States
National Museum.
Pleistocene. — San Pedro (Arnold).
Subgenus Anachis //. it A. Adams.
Shell oval-fusiform, longitudinally ribbed; spire elevated; aperture narrow; columella
straight; outer lip nearly straight, crenulated within.
AnacMs rugosa Sowerby is a characteristic species.
228. Columbella (Anachis) minima, sp. uov.
Plate IX, Fig. 8.
Shell small, resembles a young Amphissa corrugata but much slenderer; surface sculptured
by numerous transverse ridges and fine spiral sulcations; whorls six, shouldered above as in Amphissa
versicolor; aperture subquadrate; outer lip nearly straight; pillar straight, spirally striated.
Di7nensions. — Long. 6 mm.; lat. 2.4 mm.; body-whorl 3.5 mm.; aperture 2.2 mm.; defl.
28 degrees.
Distinguishable from Amphissa corrugata by slenderer form, more shouldered
whorls and less wavy transverse ridges. Pronounced a new species of Anachis by
Dr. Dall.
Type from upjier San Pedro series of San Pedro; rare. The specimen
figured is the type, which is now in the United States National Museum.
Pleistocene. — San Pedro (Arnold).
Subgenus .ffisopus Gould.
Shell fusiform, gibbous, broadly truncate in front; aperture lunate, with a posterior callous
on the body; columella smooth, vitreous; suture abnormally arcuate near the aperture.
Type, ^sopus japonicus Gould.
229. Columbella (.Ssopus) chrysalloidea Carpenter.
Plate V, Fig. 6.
Amycla chrysalloidea Cpr., Brit. Assn, Rept., 1863, p. 612; Proc. Cal. Acad. Sci., Vol. Ill, 1S64,
p. 223.
Columbella chrysalloidea Cpr., Tryon, Man. Conch., Vol. V, p. 135, PL L, fig. 42, 1883.
Astyris chrysalloidea Cpr., Keep, West Coast Shells, p. 36, 1S92.
Columbella {y£sopus) chrysalloidea Cpr., Williamson, Proc. U- S. Nat. Mus., Vol. XV, 1892, p. 213.
Shell small, with general elongate-ellipdcal oudine, or chrysalis-shaped; spire elevated, sub-
acute; whorls six, very slightly convex; surface marked by delicate spiral ridges and furrows;
238 CALIFOKNIA ACADEMY OF SCIENCES.
aperture ovate; canal short; outer lip thickened by several longitudinally elongate denticles on inner
side; inner lip curved, smooth; spiral ornamentation prominent on lower portion of columella.
Dimensions. — Long. 8.2 mm.; lat. 3 mm.; body-whorl 5.5 mm.; aperture 3.4 mm.; defl.
44 degrees.
Rare in the lower San Pedro series at Deadman Island and San Pedro; not
uncommon in the upper San Pedro series at San Pedro. Found also in the Pleisto-
cene at Twenty-sixth street, San Diego. The specimen figured is from the upper
San Pedro series at San Pedro, and is now in the collection of Delos Arnold.
Living. — San Pedro to San Diego (Cooper).
Pleistocene. — San Pedro; San Diego (Arnold).
230. Columbella (.ffisopus) oldroydi, sp. nov.
Plate VI, Fig. 7.
Shell small, slender, fusiform; spire elevated; apex rounded; whorls seven, convex; first
three whorls smooth, remainder, with exception of body-whorl, ornamented with about eighteen
transverse ridges and two or three rather indistinct spiral grooves, the whole giving a cancellate
appearance to the surface; on the body-whorl the transverse and spiral sculpture are of about equal
prominence, the transverse sculpture being more subdued than on the whorls above it; suture quite
deeply impressed; aperture narrow, elliptical; pillar truncated anteriorly; outer lip smooth, thin;
inner lip smooth.
Dimensions. — Long. 9 mm.; lat. 2.6 mm.; body-whorl 5 mm.; aperture 3 mm.; defl.
24 degrees.
Distinguishable from A. chrysalloidea by slenderer form, prominently sculp-
tured surface, deeper suture, and smooth inner lip. Pronounced a new species by
Dr. Dall.
Lower San Pedro series at Deadman Island; rare. The specimen figured is
the type, and is now in the collection of Mrs. Oldroyd.
Pleistocene. — San Pedro (Arnold).
Subgenus Astyris //. ct A. AJams.
Shell oval-fusiform, smooth or transversely striated; aperture oval; inner lip smooth, not
callous; outer lip sinuous posteriorly, crenulated within.
Astyris clausilimforme Kiener is a characteristic species.
231. Columbella (Astyris) californiana Gaskoin.
Pl.\te X, Fk;. 9.
Columbella {Astyris) californiatia Gask., Proc. Zool. Soc, 1851, p. 12.
Columbella californiana Gask., Cpr., Brit. Assn. Rept., 1856, p. 341.
This species resembles A. cjausapata quite closely, but differs from it in the
following respects: it is slightly broader, has more swelling whorls, more prominent
AENOLD — THE PALEONTOLOGY AND STEATIGKAPHY OF SAN PEDKO. 239
spiral lines on the lower part of the body-whorl, does not have the overla^^ping
apjiearance of the wliorls at the suture as much as in A. gausapata, has a less heavy
shell, and has a less glossy surface. SiJecimen identified by Dr. Dall.
Rare in the lower San Pedro series at Deadman Island, also found in the
lower San Pedro series at San Pedro. The specimen figured is from the lower San
Pedro series at Deadman Island, and is now in the collection of Delos Arnold.
Living. — Santa Barbara to San Diego (Carpenter).
Pleistocene. — San Pedro (Oldroyd; Arnold).
232. Columbella (Astyris) gausapata Gould.
Plate X, Fig. 8.
Columbella gausapata Gld. , Proc. Bost. Soc. Nat. Hist., 1S50, p. 170; Wilkes' Expl. Exped.,
Vol. XII, p. 267, PI. XIX, fig. 337, 1852.
Nassa pedroana Con., Pac. R. R. Rept.. Vol. V, p. 327, PI. VI, fig. 48, 1S56.
Amycla gausapata Gld., Cpr., Brit. Assn. Rept., 1863, p. 662. Gabb, Pal. Gal., Vol. II, p. 76, 1S69.
Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 229.
Astyris gausapata Gld., Keep, West Coast Shells, p. 35, fig. 15, 1892.
Colu7nbella (^Astyris) gausapata Gld., Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1S92, p. 213.
Shell small, rather heavy; spire elevated; apex acute; whorls seven, slightly convex; body-
whorl ventricose, slightly angulated; whorls smooth except for delicate incremental lines; suture
depressed, distinct; columella recurved and striated on outside with faint spiral ridges and grooves;
aperture elongate-ovate; canal prominent, slightly curved; outer lip thickened with a row of spirally
elongate denticles; inner lip smooth.
Dime7isio7ts. —1.0-ng. 11 mm.; lat. 5 mm.; body-whorl 7 mm.; aperture (not including
canal) 3 mm-X i-9 mm.; defl. 35 degrees.
Distinguishable from C. californiana by much longer canal, thicker shell, and
more prominent denticulation of outer lip; distinguishable from C. tuberosa by
broader spire and less angulated body-whorl; distinguishable from var. carinata by
lack of keel, and slenderer sjiire. Specimens identified by Dr. Dall.
Found in all of the formations at all of the localities in the vicinity of San
Pedro. Found also in the Pleistocene at the bath-house, Santa Barbara; at Barlow's
ranch and the old irrigating ditch, Ventura; and at Twenty-sixth Street and Pacific
Beach, San Diego. Much rarer than var. carinata. The specimen figured is from
the upper San Pedro series at San Pedro, and is now in the collection of Delos
Arnold.
Living. — Alaska to San Diego (Cooper).
Pleistocene. — Santa Barbara to San Diego (Cooper): San Pedro; Ventura;
Santa Barbara; San Diego (Arnold).
Pliocene. — Kirker's Pass (CoojJer).
240 CALIFORNIA ACADEMY OF SCIENCES.
233. Columbella (Astyris) gausapata Guu/d, var. carinata Hinds.
Plate X, Fig. 10.
Columbella carinata Hds., Voyage Sulphur, p. 39, PI. X, figs. 15, 16, 1844. Cpr., Brit. Assn. Rept.,
1863, p. 662. Tryon, Man. Conch., Vol. V, p. 116, PI. XLVII, figs. 35-39, 1883.
Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 213.
Amycla carhiala Hds., Gabb, Pal. Cal., Vol. II, p. 76, 1869.
Aslyris gausapata var. carinata Hds., Keep, West Coast Shells, p. 35, 1892.
Shell like A. gausapata, except that it has a distinct keel on the upper part of
the whorl. A large series of shells shows mutations between the typical gausapata
and this variety. An extreme keeled form gives the following dimensions: Long.
8 mm.; lat. 4.1 mm.; body-whorl 5 mm.; aperture 3.5 mm.
Common in all of the formations at all of the localities in the vicinity of
San Pedro; much commoner than C. gausapata. Found also in the Pleistocene at
the old irrigating ditch north of Ventura; at bath-house, Santa Barbara; and at
Spanish Bight, San Diego.
The specimen figured is from the upper San Pedro series at San Pedro, and
is now in the collection of Delos Arnold.
Living. — Santa Barbara to San Diego (Cooper).
Pleistocene. — Santa Barbara to San Pedro (Cooper): San Pedro; Ventura;
Santa Barbara; San Diego (Arnold).
234. Columbella (Astyris) tuberosa Carpenter.
Plate X, Fig. 7.
Amycla tuberosa Cpr., Brit. Assn. Rept., 1863, p. 662; Ann. & Mag. Nat. Hist., 3rd Sen, Vol. XV,
1865, p. 398. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 229.
Astyris tuberosa Cpr., Stearns, Proc. Cal. Acad. Sci., Vol. V, 1873, p. 81. Keep, West Coast
Shells, p. 36, 1892.
Columbella tuberosa Cpr., Tryon, Man. Conch., Vol. V, p. 135, PI. L, figs. 40 and 41, 1883.
Columbella {Astyris) tuberosa Cpr., Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 213^
PI. XX, fig. 6.
Shell small, slender; spire elevated; acute apex; whorls seven, only slightly convex; body-
whorl angulated, lower portion decidedly concave and ornamented with narrow grooves and ridges;
surface of upper whorls smooth except for delicate incremental lines; suture distinct; aperture ovate,
and less than one-half the length of shell; anterior end of columella slender; outer lip thickened
by row of tubercles on inner side; inner lip smooth; canal short, straight.
Dimensions. — Long. 6.5 mm.; lat. 2.8 mm.; body-whorl 4 mm.; aperture 2.9 mm.; defl.
22 degrees.
Distinguishable from other members of genus by slender spire and angulated
body-whorl.
Rare in the lower San Pedro series at Deadman Island and San Pedro; and
in the upper San Pedro series at Crawfish George's, Los Cerritos, San Pedro,
and Deadman Island. Found also in the Pleistocene at Spanish Bight, San Diego;
ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDKO. 241
and at bath-house, Santa Barbara. The specimen figured is from the upper Ban
Pedro series at Sau Pedro, and is now in the collection of Delos Arnold.
Living. — Neah Bay to San Diego (Cooper).
Pleistocene. — Santa Barbara to San Pedro (Cooper): San Pedro; San Diego;
Santa Barbara (Arnold).
Pliocene. — San Diego well (Dall).
Genus Amphissa H. £ A. ALlams.
Shell bucciniform, longitudinally ribbed; spire elevated; aperture rather wide, enlarging
below, and terminating in a wide anterior sinus; inner lip callous, plicate below; outer lip not thickened
on margin, plicate within.
Amphissa corrugata Reeve is a characteristic species.
235. Amphissa corrugata Reeve.
Biiccinum corrugatum RvE., Icon. Conch., PI. IV, fig. no, 1846.
Truncaria corrugata RvE., CPR., Brit. Assn. Rept. , 1863, p. 662.
Comitiella {Amphissa) corrugata RvE., Cpr., Brit. Assn. Rept., 1866. Gaeb, Pal. Cal., Vol. II,
p. 74, 1869.
Amphissa corrugata RvE., Tryon, Man. Conch., Vol. V, p. 197, PI. LXIII, fig. 66, 1883.
Cooper, 7th Ann. Rept. Cal. St. Min., 1S88, p. 228. Keep, West Coast Shells,
p. 34, fig. 14, 1892.
Shell small, solid, fijsiform; spire elevated; apex acute; whorls seven, slightly convex, with
about eighteen to twenty rather wavy, slightly oblique, rounded, transverse ridges extending firom
suture to suture; spiral ornamentation consists of numerous fine, raised lines in the interspaces
between the transverse ridges; suture impressed, distinct; aperture rhomboidal, narrow; outer lip
lirate within; inner lip incrusted, smooth; canal short, recurved; pillar spirally lined externally.
Dimensions. — Long. 19 mm.; lat. 9 mm.; body-whorl 13.5 mm.; aperture 10 mm.; defl.
52 degrees.
The Pliocene forms are much smaller than the one described above (a Pleisto-
cene specimen). Carpenter mentions the shells as becoming dwarfed in deep water
(40 fathoms).
Rather common in Pliocene and lower San Pedro series at Deadraan Island;
rare in upper San Pedro series at San Pedro, Los Cerritos, and Crawfish George's.
Found also in the Pleistocene at the bath-house, Santa Barbara.
Living. — Alaska to San Diego (Cooper).
Pleistocene. — Santa Barbara to San Diego (Cooper): San Pedro; Santa Bar-
bara (Arnold).
Pliocene. — San Diego well (Dall): San Pedro (Arnold).
( 31) Marcb 21, 19o;i.
242 CALIFOKNIA ACADEMY OF SCIENCES.
236. Amphissa ventricosa, sp. nov.
Plate V, Fig. 11.
Shell small, broadly fusiform; spire elevated; whorls five or six, evenly convex, with twelve
or thirteen strong, rounded, transverse ridges; interspaces sculptured with prominent, regular, equi-
distant, raised spiral lines, of which there are five or six on the penultimate whorl; suture deeply
impressed, distinct; aperture semicircular; outer lip ventricose, thickened with row of teeth; inner
lip smooth, incrusted; pillar straight; spirally sculptured on outside; no canal.
Dime7isio7is. — Long. 12 mm.; lat. 6 mm.; body-whorl 8.6 mm.; aperture 6 mm.; defl.
43 degrees.
Resembles A. bicolor somewhat, but distinguishable from this species by lack of
canal, stronger ribs, and more convex whorls; distinguishable from other members
of genus by thin shell, ventricose whorls, semicircular aperture and lack of differ-
entiated canal. Dr. Dall examined the type and pronounced it a new species.
Rare in lower San Pedro series of Deadman Island. The specimen figured
is the type, which is from the lower San Pedro series at Deadman Island, and is now
in the United States National Museum.
Pleistocene. — San Pedro (Arnold).
237. Amphissa versicolor Ball.
Amphissa versicolor Dall, Am. Jour. Conch., Vol. VII, 1872, p. iii. Tryon, Man. Conch.,
Vol. V, p. 197, PI. LXIII, fig. 67, 1883; Proc. U. S. Nat. Mus., Vol. XV, 1892,
p. 213, PI. XX, fig. 9.
Amphissa corrjigata Rye., Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 228 (in part).
Shell small, fusiform; apex acute; whorls seven, convex, slightly angular above; body-whorl
slightly ventricose; surface ornamented with about fourteen rounded, obliquely transverse ridges, and
several distinct, raised, spiral lines in the interspaces; suture quite deeply impressed; aperture sub-
elliptical; outer lip slightly thickened by lirated ridges on inner side; inner lip incrusted, smooth;
columella spirally sculptured externally; canal short, broad, recurved.
Dimensions. — Long. 10.2 mm.; lat. 5 mm.; body-whorl 7 mm.; aperture 5 mm.; defl.
47 degrees.
Distinguishable from A. corrugata by more ventricose body-whorl, relatively
longer columella and shorter spire, more angulated whorls, deeper suture and less
numerous but more oblique and larger transverse ridges. Specimen identified by
Dr. Dall.
Found in lower San Pedro series at Deadman Island, and upper San Pedro
series at Crawfish George's, Los Cen-itos, and Deadman Island. Found also in the
Pleistocene at Pacific Beach, San Diego.
Living. — San Pedro (Dall).
Pleistocene. — San Pedro; San Diego (Arnold).
ARNOLD — THE PALEONTOLOGY AND STKAtlGEAPHY OF SAN PEDRO. 243
Family LXI. MURICID^.
Genus Murex Linne.
Shell ovate or oblong; spire prominent; whorls convex, crossed by three or more con-
tinuous varices; aperture ending below in a canal, which is generally partly closed.
Murex tenuispena Lara, is a characteristic species.
Subgenus Chicoreus Montfort.
Shell ovate-pyriform; varices foliated and sometimes spinose; canal short, curved, wide,
nearly closed.
Murex adustus Lam. is a characteristic species.
238. Murex (Chicoreus) leeanus Dull.
Plate VII, Fig. 1.
Murex (Chicore7is) leeanus Dall, Proc. U. S. Nat. Mus., Vol. XII, 1890, p. 329, PI. VII, fig. i.
Shell large, strong, angular in outline; apex sharp; whorls five or six, angular, flat to con-
cave above; each whorl ornamented with three varices, which extend out into long, rather sharp
spines; the varices toward the apex fall short of completing a whole whorl, so that they are slightly
spirally arranged; a faint node on angle between each pair of varices; surface sculptured with delicate
squamose, spiral cinguli, with chiseled grooves between; suture deeply impressed, wavy; aperture
elliptical; outer lip smooth; inner lip slightly projecting, smooth; canal long, narrow, slightly curved,
covered; older termini of canal visible on pillar at left of canal.
Dimensions. — Long. 55 mm.; lat. 43 mm.; body-whorl 47 mm.; aperture 17 mm.
A large, showy shell, easily distinguishable by the long, sharp varical spines.
Specimens identified by Dr. Dall.
Rare in upper San Pedro series at San Pedro and Crawfish George's. The
drawing of this species is a composite, and was made from two iraj^erfect specimens
from the upper San Pedro series at San Pedro, which are now in the collection of
Delos Arnold.
Living. — Cerros Island, off Lower California (Dall).
Pleistocene. — San Pedro (Arnold).
239. Murex (Chicoreus?) trialatus Sowerby.
Murex trialatus Sby. , Proc. Zool. Soc, 1840, p. 143. Tryon, Man. Conch., Vol. II, p. 113,
PI. XXXIV, fig. 372, 1880.
Murex califorjiicus Hds., Proc. Zool. Soc, 1843, p. 128. Voyage Sulphur, PI. Ill, figs. 9 and 10,
1844. Tryon, Man. Conch., Vol. II, p. 113, PI. XXXIV, fig. 375; PI. XXXV,
fig. 287, 1880.
Muricidea californica Hds., Cpr., Brit. Assn. Rept., 1863, p. 663. Gabb, Pal. Cal., Vol. II,
p. 69, 1869.
Shell small, fusiform; spire elevated, subacute; whorls five, convex; body-whorl over three-
fourths length of shell; varices three, thick and rounded, elevated on angle of whorl to sharp,
244 CALIFORNIA ACADEMY OF SCIENCES.
prominent nodes; a single, less prominent, rounded node on angle between each pair of varices;
spiral sculpture of fine raised lines, with fine incremental lirute in the interspaces; aperture ovate;
canal long, narrow, slightly recurved, and generally covered by overgrowing sides; lower part of
columella slightly widened; outer lip thickened by varix, smooth inner surface; inner lip slightly
raised and smoothly enameled.
Dinie7isions. — Long. 38 mm.; lat. 21.5 mm.; body whorl 30 mm.; aperture 22.5 mm.; canal
1 1 mm. ; defl. 60 degrees.
Hare in upper San Pedro series at San Pedro, Deadman Island, and Craw-
fish George's.
Living. — Baulinas Bay to San Diego (Carpenter) : Lower California (Hemphill ) .
Pleistocene. — San Pedro (Arnold).
Subgenus Pteronotus Sivainson.
Shell triangular; varices fin-like or foliated; canal moderate, closed, somewhat curved.
Murex trigonulus Lam. is a characteristic species.
240. Murex (Pteronotus) festivus Hinds.
Murex festivus Hds., Proc. Zool. Soc, 1843, p. 127; Voyage Sulphur, p. 9, PI. Ill, figs. 13 and
14, 1844. Tryon, Man. Conch., Vol. II, p. 116, PI. XXXV, fig. 383, 1880.
Pteronotus festivus Hds., Cpr., Brit. Assn. Rept., 1863, p. 663. Gabb, Pal. Cal., Vol. II, p. 70.
1869. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 261. Dall, Trans. Wagner Inst.
Sci., Vol. Ill, Part I, 1890, p. 142. Keep, West Coast Shells, p. 22, fig. 3, 1892.
Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 216.
Shell of moderate size, fusiform; spire elevated, short; whorls si.x, subangulate, crossed by
three prominent, reflexed, frill-like varices; a single rounded node between each set of varices;
numerous spiral lines, which are almost obsolete, ornament the intervarical spaces; suture deeply
impressed; aperture pyriform; outer and inner lips smooth; canal long, narrow, slightly curved;
columella squamose on outside, widened slightly.
Dimensions.- — Long. 40 mm.; lat. 21 mm.; body-whorl 31 mm.; aperture, not including
canal, 12 mm.; canal 11 mm.; defl. 65 degrees.
This species is characterized by the sharp, frill-like varices said by Dr. Dall
to resemble quite closely /". (le./^^i/iy Gabb, of tlie Miocene of San Domingo and Hayti,
and the Pliocene of Florida.
Rare in the lower San Pedro series at Deadman Island; not uncommon in the
upper San Pedro series at Deadman Island, Crawfish George's, San Pedro and Los
Cerritos. Found also in the Pleistocene at Spanish Bight, San Diego.
Living. — San Pedro to San Diego; Lower California (Cooper).
rieistocene. — Santa Barbara; San Diego (Cooper): San Pedro; San Diego
(Arnold).
Subgenus Pterorhytis Conrad.
Varices wing-like; aperture usually dentate within the outer lip, with a produced tooth
near its base.
Type, Murex nuttalli Conrad.
ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 245
241. Murex (Pterorhytis) foliatus iiartijn.
Cerostoma foliaiufn Martvn, Univ. Conch., No. 66, PI. XXIV, fig. i, 1784. Cpr., Brit. Assn.
Rept, 1863, p. 663. Keep, Common Sea Shells, PI. XIV, fig. 5, 1881; West Coast
Shells, p. 27, 1892.
Murex foliatus Mart., Tryon, Man. Conch., Vol. II, p. 113, PI. XXXIV, figs. 370, 371, 373, 1880.
Pterorhytis foliahis Mart., Cooper, Bull. No. 4, Cal. St. Min. Bureau, Part 3, 1894, p. 24.
Shell small, broadly fusiform, with extended varices; spire elevated, subacute; whorls three
to four; varices three, widely expanded, foliated on anterior side; one prominent node on convex
surface of whorl between each set of varices; aperture subovate, with smooth outer and inner lip;
canal long, narrow, expanding anteriorly, generally covered by overgrowing lips.
Dimensiotis. — Long. 35 mm.; lat. 21 mm.; body-whorl 26.5 mm.; aperture 21 mm.;
canal 10 mm.
Distinguislmble by the wing-like, foliated varices. The specimen tleseribed
was too poor to figure.
Rare in the upper San Pedro series of San Pedro; one specimen found.
Living. — Vancouver to Oregon (Carpenter): Sitka to Santa Barbara; Asia
(Cooper).
Pleistocene. — San Pedro (Arnold): Puget Sound; San Diego; Santa Barbara
Islands (Carpenter): San Joaquin Bay, Orange County (Bowers).
242. Murex (Pterorhytis) nuttalli Conrad.
Cerostoma nuttalli Con., Jour. Phil. Acad. Nat. Sci., Vol. VII, 1837, p. 264, PL XX, fig. 22. Cpr.,
Proc. Zool. Soc, 1856, p. 229; Brit. Assn. Rept., 1863, p. 663. Tryon, Struct, and Syst.
Conch., Vol. II, p. 105, PL XLIII, fig. 8, 1883. Cooper, 7th Ann. Rept. Cal. St. Min.,
1888, p. 233. Keep, West Coast Shells, p. 26, fig. 8, 1892.
Pterorhytis nuttalli CoN., Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 215.
Shell of medium size, heavy, thick; spire elevated, subacute; whorls four, convex, each with
three prominent varices, which are rather smooth behind, but showing their lamellar structure in
front; each varix is connected with the analogous vari.x on the preceding whorl, but the varices being
slightly less than one-third of a revolution apart cause the radiating ridges formed by the connected
varices to be spirally twisted; intervarical spaces prominently spirally ribbed, the ribs extending on
to the backs of the varices; seven or eight prominent spiral ribs on the body-whorls; aperture ellip-
tical; outer lip with eight or nine internal teeth, each corresponding to one of the external sulcations
of the body-whorl; sometimes with prominent tooth near anterior portion of outer lip; inner lip
smooth; canal rather short, covered; lower portion of columella expanded, rough, subpunctate.
Dimensions. — Long. 65 mm.; lat. 34 mm.; body-whorl 50mm.; aperture 25 mm.; canal
14 mm.
This species may be only a variety of P. foliatus Mart. It is distinguishable
from the latter species by the greater prominence of its spiral sculpture, and it.':^
lower varices.
Rare in upper San Pedro series at Deadman Island and Los Cerritos.
Living. — Paulinas Bay to San Diego (Cooper).
Pleistocene. — San Pedro (Arnold): San Diego (Cooper).
246 . CALIFORNIA ACADEMY OF SCIENCES.
243. Murex (Pterorhytis) monoceros Soiverby.
Murex monoceros Sby., Proc. Zool. Soc, 1840, p. 143. Tryon, Man. Conch., Vol. II, p. 115,
PI. XXXV, figs. 388, 389, 1880.
Muricidea (^Phyllonotus) paucivaricata Gabb, Pal. Cal., Vol. II, p. 43, PI. XIV, fig. i, 1869 {fide
Tryon).
Muricidea paucivaricata Gabb, Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 252 {^fide Tryon).
Shell moderate in size, fusiform; spire nearly as long as aperture; whorls seven, subangulated,
bearing eight or nine large, longitudinal ribs which develop into prominent nodes on the angle;
suture irregular, appressed, distinct; aperture ovate; canal rather short, narrow, recurved, and often
overgrown by two lips; outer lip thickened, denticulated with four sharp teeth; inner lip slightly
projecting, smooth, incrusted; columella widened; varices two or three, never prominent, sometimes
obsolete; numerous small revolving ribs crossed by small squamose plates; body-whorl sometimes
ornamented with five or six, quite prominent, rounded, spiral ridges.
Dimensio7is. — Long. 46 mm.; lat. 23 mm.; body-whorl 32 mm.; aperture, including canal,
26 mm.; canal 9 mm.; defl. 50 degrees.
Distinguishable from M. calif ornica by denticulated outer lip, lack of varices,
thicker shell, and generally larger size. Originally described from Pleistocene
specimen.
Rare in upper San Pedro series of San Pedro.
Living. — Lower California?
Pleistocene. — Santa Barbara; San Diego (Cooper): San Pedro (Arnold).
Genus Monoceros Lamarck.
Shell ovate; last whorl large; spire rather elevated; aperture semilunar; inner lip wide and
flattened; outer lip crenated, with a prominent tooth usually at the forepart.
Monoceros lugubre Sowb. is a characteristic species.
244. Monoceros engonatum Conrad.
Monoceros engonatum CoN., Jour. Phil. Acad. Nat. Sci., Vol. VII, 1837, p. 264, PI. XX, fig. 17.
Cpr., Brit. Assn. Rept., 1863, p. 663. Gabb, Pal. Cal, Vol. II, p. 75, 1869. Tryon,
Man. Conch., Vol. II, p. 195, PI. LXI, figs. 304, 1880. Cooper, 7th Ann. Rept.
Cal. St. Min., 1888, p. 251. Keep, West Coast Shells, p. 29, fig. 10, 1S92. Willi-
amson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 214.
Monoceros unicarinatum RvE., Icon. Conch., Sp. i.
Shell of medium size, fusiform; whorls six, angular, flattened to concave above and below;
spirally sulcate, sulci with tranverse lamellar strite; suture deeply appressed, distinct; aperture sub-
elliptical; outer lip effuse, dentate within; inner lip slightly flattened, smooth; canal deep, narrow,
recurved; pillar twisted, squamose.
Dimensions.- — -Long. 40 mm. ; lat. 20 mm.; body-whorl, 30.5 mm.; aperture 24 mm.; defl.
55 degrees.
This is a variable species. Specimens showing the scaly surface of var.
spiratum grade over into the smooth form; the sharp-keeled forms merge into those
which approach very near to M. lajnlloides. Some specimens have thin and smooth
ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDEO. 247
outer lips, while others are strongly dentate. Of fifty specimens from the San Pedro
Pleistocene only three have the characteristic tooth developed, thus showing that in
these earlier forms this distinguishing characteristic was only occasional. The
scaly specimens are generally the strongest keeled. This latter form is the var.
spiratum of Blainville.
Found in all of the lower and upper San Pedro series localities in the vicinity
of San Pedro. Found also in the Pleistocene at Barlow's ranch, Ventura; and at
Pacific Beach, San Diego.
Living. — Baulinas Bay to San Diego (Cooper).
Pleistocene. — San Pedro; San Diego (Cooper) : Lake Merced, San Mateo
County; San Pedro; San Diego; Ventura (Arnold).
245. Monoceros lapilloides Conrad.
Purpura {Monoceros) lapilloides Con., Jour. Phil. Acad. Nat. Sci., Vol. VII, 1837, p. 265, PL XX,
fig. 18.
Mo7ioceros lapilloides Con., = M. punclaium Gray, -f- M. brevidens Con. {fide Cpr., Brit. Assn.
Rept., 1863, p. 663). Keep, West Coast Shells, p. 28, fig. 9, 1892. Cooper, Bull.
No. 4, Cal. St. Min. Bureau, 1894, Part 3, p. 28.
Shell of medium size, purpuroid-shaped; spire elevated; apex subacute; whorls four, very
slightly conve.x; surface ornamented with nearly obsolete spiral cinguli and nearly obsolete, irregular,
wavy, transverse ridges; suture impressed, indistinct; aperture subovate; outer lip thickened, dentate;
inner lip flattened, smooth; canal short.
Dime7isions. — Long. 20.5 mm.; lat. 13 mm.; body-whorl 18 mm.; aperture 14 mm.; defl.
67 degrees.
The specimen described shows the reddish color of the live shells. Distin-
guishable from M. engonatum by much shorter spire, broader and shorter pillar, and
much less angular whorls; distinguishable from Purpura saxicola by relatively larger
spire, narrower aperture, dentate outer lip and spiral cinguli.
Bare in uj^per San Pedro series of San Pedro; one specimen.
Living. — Santa Barbara to San Diego (Carpenter): Monterey (Cooj^er).
Pleistocene. — San Pedro (Arnold): Ventura County (Bowers).
Genus Chorus Gray.
Shell laminately varicose; spinose on the shoulder; canal rather long; outer lip with a spine
as in Monoceros.
Tyjie, Chorus helcheri Hinds.
246. Chorus belcheri Hinds.
Murex belcheri Hds., Proc. Zool. Soc, 1843, p. 127; Voyage Sulphur, PI. II, figs. 1-3, 1S44.
Pfeiffer, Nov. Conch., Ser. II, p. 35, PI. X, figs. 6, 7.
Chorus belcheri Hds., Cpr., Brit. Assn. Rept., 1863, p. 663. Tryon, Man. Conch., Vol. II, p. 198,
PI. LXI, fig. 309, 1880; Syst. Conch., Vol. II, p. 114, PI. XLV, figs. 43, 44, 1883.
Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 235. Keep, West Coast Shells, p. 25,
fig. 7, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 216.
248 CALIFORNIA ACADEMY OF SCIENCES.
Sliell large, broadly fusiform; spire slightly elevated; whorls five, sharply angulated, with
eight or nine nearly obsolete varices which rise to prominent blunt nodes or spines on the angle of
whorl; incremental lines prominent; spiral liration on upper whorls; suture impressed, distinct;
aperture ovate; outer lip not thickened, effuse; inner lip incrusted; columella widened; umbilicus
perforate; canal long, narrow, curved backwards.
Dime7isions. — Long. 90 mm.; hit. 62 mm.; body-whorl 78 mm.; aperture 40 mm.; canal
25 mm.; defl. 95 degrees.
A beautiful shell, one of the largest gastrojiods found in this fortnation.
Rare in upjier San Pedro series at Crawfish George's, Los Cerritos, and San
Pedro. Found also in the Pleistocene at Barlow's ranch, Ventura.
Living. — Catalina Island to San Diego; Lower California (Cooper) : Sitka
(Carpenter): Japan (Tryon).
Pleistocene. — San Pedro (Cooper; Arnold): Ventura (Arnold).
Pliocene. — San Diego well (Dall).
Genus Eupleura //. & A. Adams.
Shell ranelliform, with a pair of lateral varices, one on either side, and intermediate smaller
varices; aperture dentate within.
Eupleura caudata Say is a characteristic species.
247. Eupleura muriciformis Broderip.
Plate IX, Fig. 16.
Ranella muriciformis Brod., Proc. Zool. Soc, 1832, p. 179. Rve., Conch. Icon., Ranella, PI. VII,
fig. 34, 1844.
Ranella plicaia Rye., Proc. Zool. Soc, 1844, p. 13S; Conch. Icon., Ranella, PI. VII, fig. 33, 1844.
Ranella triquetra RvE., Proc. Zool. Soc, 1844, P- I39i Conch. Icon., Ranella, PI. VII, fig. 41,
1844. Cpk., Brit. Assn. Rept., 1863, p. 667; 1856, p. 201. Gabb, Pal, Vol. II,
p. 73, 1869. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 262.
Eupleura muriciformis Brod., Cpr., Brit. Assn. Rept., 1856, p. 182. Trvon, Man. Conch., Vol. II,
p. 168. PL XXXIX, figs. 501, 502, 504, 505, 1880. Dall, Trans. Wagner Inst. Sci.,
Vol. Ill, Part I, 1890, p. 145.
Eupletira muriciformis (var.?) unispinosa Dall, Proc U. S. Nat. Mus., Vol. XIV, 1891, p. 174,
PL VI, fig. 5.
Shell of medium size, quite broadly fusiform, solid; spire elevated; whorls five, subangular
at lower one-third, concave to straight above, convex below; whorls crossed by varices at every two-
thirds revolution, the two varices on the body-whorl and the ne.\t varix posterior to these are
prominent, the others being obsolete in most cases; the varices are generally thin, webbed, and with
six obsolete spines; the spine at the shoulder is the most prominent, but the second spine, counting
forward, is the one corresponding to the axis of the intervarical nodes; the web between the shoulder
spine and the suture is bent forward; spiral ridges correspond to each spine; four nodes on angle of
whorl between each pair of varices; suture deeply impressed, distinct; aperture elliptical; outer lip
thickened by six dentiform calluses, one each between each pair of external spiral ridges; canal long,
narrow, nearly straight.
Dimensions. — Long. 25.5 mm.; lat. 14 mm.; body- whorl 20.5 mm.; aperture, including
canal, 17.5 mm.; canal 7 mm.; defl. 70 degrees.
ARNOLD — THE PALEONTOLOGY AND STKATIGKAPHY OF SAN PEDRO. 249
The prevailing t^ype of the San Pedro fossil specimens does not correspond
exactly to any of tlie descriptions of the living varieties of this species as given by
Dr. Dall in the paper cited above. It comes nearest to var. unispinosn, differing
from that form by having a straight canal. The name var. pleistocenensis is suggested
for the San Pedro fossil foi'm.
Rare in the upper San Pedro series of San Pedro; one specimen from lower
San Pedro series at Deadman Island. Found also in the Pleistocene at Twenty-
sixth Street, San Diego. The specimen figured is from the upper San Pedro series
at San Pedro, and is now in the collection of Delos Arnold.
Living. — California to Venezuela (Dall).
• Pleistocene. — San Pedro (Arnold): San Diego (Dall; Cooper; Arnold):
Pacific coast of Lower California; head of the Gulf of California (Dall).
248. Eupleura muriciformis var. curta, var. nov.
Plate VIII, Fii:. 9.
Shell small, broadly fusiform; whorls four, angular, flat above, convex below; two sharp
spiral ridges on upper whorls, si.x on body-whorl corresponding to obsolete spines on varix; one
prominent varix on body-whorl, other varices obsolete; whorls crossed by prominent, narrow,
rounded ridges, of which there are twelve on the penultimate whorl; aperture elliptical; outer lip
thickened by a row of six denticles; inner lip smooth, projecting; canal short, narrow.
Dimensions.- — Long. 15 mm.; lat. 10 mm.; body-whorl 11 mm.; aperture, including canal,
9.5 mm.; canal 2.2 mm.; defl. 65 degrees.
Differs from E. muricifonim in having obsolete varices, transverse ridges
instead of nodes, much shorter canal, and in general much stronger sculpture.
The type, which is figured, is from the upper San Pedro series at San Pedro,
and is now in the United States National Museum.
Pleistocene. — San Pedro (Arnold).
Genus Trophon Mont fori.
Varices numerous, lamelliform or laciniated; spire prominent; aperture ovate; canal open,
usually turned to the left; shell white, often dark colored within the aperture.
Tro'phon clatludtm^ Linn, is a characteristic species.
Subgenus Boreotrophon Fischer.
249. Trophon (Boreotrophon) cerritensis, sp. nov.
Pl.\te VI, Fig. 6.
Shell of medium size, elongate-fusiform, heavy; whorls six, angular, with angle in middle,
crossed by about eighteen strong, transverse ribs; lower portion of whorls ornamented with two or
three strong, spiral ridges, one of which- is on the angle, the two systems of ridges giving a can-
cellated surtace; body-whorl and columella cancellated; suture deeply impressed, distinct; aperture
( il ) Maivb 24. 1903.
250 CALIFORNIA ACADEMY OF SCIENCES. '
elliptical; outer lip thickened, smooth within; iiim r lip incrusted, smooth; columella only faintly
squamose, curved and slighdy twisted; canal rather short, narrow.
Dimensions. — Long. 33 mm.; lat. 15 mm.; body-whorl 23 mm.; aperture, including canal,
18 mm.; canal 7 mm.; defl. 44 degrees.
The largest of the Troplwns so far found in this locality. The adult of this
shell resembles var. prrecur^ior, but is distinguishable from that species by its larger
size, heavier shell, more prominent spiral ridges, pro23ortionally shorter canal, and in
having the angle near the middle of the wiiorl, rather than posterior to the middle;
distinguishable from 2\ ^tiuirti by heavier shell, more numerous and much heavier,
lower and more rounded, transverse ridges, shorter canal, and by having the angle in
the middle of the whorl. The young of T. cerritensis resembles 7\ i^edroana some-
what, but may be distinguished from that species by its heavier shell, more depressed
outline and much shorter canal. An adult found at Los Cerritos has fewer transverse
ridges and a higher angle than the type. Type from lower San Pedro series of
Deadman Island. Said by Dr. Dall to be near 2\ craticnlattis Fabricius.
One adult specimen (type) and five juniors found in lower San Pedro series
at Deadman Island; one specimen from Los Cerritos in ujiper San Pedro series.
The specimen figured is the type, whicii In from the lower San Pedro series at
Deadman Island, and is now in the United States National Museum.
Pleistocene. — San Pedro (Arnold).
250. Trophon (Boreotrophon) gracilis Perry.
Plate VI. Fig. 8.
Polyplex gracilis Perry, Conch , PI. IX, fig. 4.
Trophon 7n7tllicostatus (noi oiK^CH.) Gxhh. Pal. Cal., Vol. II, p. 70, 1S69 (in part). Cooper, 7th
Ann. Rept. Cal. St. Min., 1888, p. 26S (in part).
Shell of medium size, lusilorm; sp're elevated; whorls five or si.x, sharply angular, crossed
by eight or nine frill-like varices, which fle.x forward and are only slightly ccjronate on angle; surface
smooth; suture deeply impressed, giving tabulate appearance to upper part of whorl; apertura
elliptical; outer lip effuse, smooth within; inner lip smooth; columella long, slightly twisted; canal
long, narrow, recurved.
Dimensions. — Long. 26 mm.; lat. 13 mm.; body-whorl ig 5 mm ; aperture 16.2 mm.; canal
7.7 mm.; defl. 62 degrees.
Distinguishable by frill-like varices and lack of spiral sculpture. Specimens
identified by Dr. Dall. This species is the T. mii Uicostatus of most western col-
lectors. It differs from that species in having fewer, but more prominent varices,
and in being a broader shell.
Rare in Pliocene and lower San Pedro series of Deadman Island. Found
also in the Pleistocene at bath-house, Santa Barbara. The specimen figured is from
the Pliocene of Deadman Island, and is now in the collection of Delos Arnold.
Livvir/. — Circumpolar; Sitka to Monterey (Cooper).
Pleistocene. — Santa Barbara (Cooper; Arnold): San Pedro (Arnold).
Pliocene. — San Pedro (Arnold).
ARNOLD — THE PALEONTOLOGY AND STRATlGlUPHY OF SAN PEDRO. '251
251. Trophon (Boreotrophon) multicostatus Eschseholtz.
Pi.ATK VI, Fig. 9.
Miirex mullicostahis EscH., Zool. Atlas, \'ol. II, p. 11, PL IX, fig. 4, 1829. Kuster, Afurex,
p. 45, PI. XVI II, fig.s. 5 and 6, 1837.
Trophon inullicostaius EscH., H. & A. Adams, Gen. Rec. Moll., Vol. i. p. 77. Cpr., Rrit. Assn.
Rept., 1863, p. 663 (in jiart). Tryon, Man. Concli., Vol. II, p. 141, PI. XXXI, fig.
316, 1880. Cooper, 7tli Ann. Rept. Cai. St. Min., 18S8, p. 269 (in part). Keep,
West Coast Shells, p. 21, 1S92 (in part).
Shell small, tiisiform; whorls five, angular above, with twelve to fourteen raised varices; no
spiral sculpture; aperture subelliptical; outer lip not effuse; inner lip smooth; canal short, slightly
curved.
Dimensions. — Long. 10.5 mm.; lat. 4.5 mm.; body-whorl 7 mm.; aperture, including canal,
5 mm.; canal i mm.; defl. 40 degrees.
The shell described is a small one. Distinguishable from T. (jvacilh by
having larger number of varices, le.ss prominent varices, more slender shell, a less
effuse outer lip, and less sharply angulated whorls. Identified as "7'. multicostatus
var.?" by Dr. Dall.
Rare in the lower San Pedro series at Deadman Island, and in upper San
Pedro series at San Pedro. The specimen figured is from the lower San Pedro series
at Deadman Island, and is now in the collection of Delos Arnold.
Living. — Sitka to Monterey; circumpolar (Cooper).
Pleistocene. — Santa Barbara (Cooper): San Pedro (Arnold).
252. Trophon (Boreotrophon) pedroana, sp. nov.
Plate VL Fig. P2.
Shell small, elongate-fusiform, thin; spire elevated, acute; whorls si.x, convex, with very
slight angle about one-third width from posterior margin; body-whorl slightly ventricose; whorls
ornamented with about fourteen slightly raised, rounded transverse ridges, and two faint spiral
ridges, one of which is on the angle of whorl; suture deeply impressed, distinct; aperture semiovate;
outer lip thin, not effuse; inner lip smooth; columella long and slender, smootli; canal long, narrow,
nearly straight.
Dimensions. — Long. 12 mm.; lat. 4.8 mm.; body-whorl 9 mm.; aperture, including canal,
7 mm.; canal 3 mm.; defl. 35 degrees.
The thinnest, most delicate of the Irophons of this locality. Distinguishable
from var. pr(ecitrsor by thinness, less angulation of whorl.s, less prominence of
sculpture, and simple outer lip; distinguishable from T. !<calarifonais by its thinness,
narrowness, and spiral lines; distinguishable from T. disparilis Dall by smaller size,
more numerous whorls, and more i)roniinent transverse sculpture.
Pronounced a new species by Dr. Dall, who also says that it is near 7\ dis-
parilis, whicii has been dredged at Gray's Harbor, Alaska.
Rather common in the lower San Pedro series at San Pedio and Deadman
Island; found also in upper San Podro series at Crawfish George's. The specimen
252 CALIFORNIA ACADEMY OF SCIENCES.
figured is the type, which came from the lower San Pedro series at Deadman Island,
and is now in the United States National Museum.
Pleistocene. — San Pedro (Arnold).
253. Trophon (Boreotrophon) scalariformis Gould.
Plate VI, Fig. 10.
Fiisus scalariformis Gld., Invert. Mass., p. 288, fig. 208.
Trophon scalariformis Gld., Trvon, Man. Conch., Vol. II, p. 141, PI. XXXI, fig. 314, 18S0.
Shell small, fusiform, spire elevated, subacute; whorls four or five, convex, crossed by about
thirteen prominent rounded ribs, most prominent in middle of whorl; body- whorl ventricose;
suture impressed, distinct; aperture broadly ovate; outer lip slightly effuse; inner lip curved,
smooth; columella long, rather narrow, curved, smooth; canal of medium length, narrow.
Dimensions. — Long. i6mm. ; lat. 7.5 mm. ; body-whorl 10.5 mm.; aperture, including canal,
8 mm.; canal 3 mm.; defl. 44 degrees.
Somewhat resembles T. multicostatus, but is distinguishable by lack of angula-
tion in whorls, longer columella and canal, but rather more ventricose body-whoid;
easily distinguishable from 7\ pedronna by more depressed aspect of .shell and lack
of spiral lines. Very faint spiral lines .sometimes visible. Specimens identified by
Dr. Dall.
Rather common in lower San Pedro series, rare in Pliocene of Deadman
Island; found in the lower San Pedro series at San Pedro; and in the upper San
Pedro series at Crawfish George's. The specimen figured is from the lower San
Pedro series at Deadman Island, and is now in the collection of Delos Arnold.
Living. — Circumboreal. Gulf of St. Lawrence.
Pleistocene. — San Pedro (Arnold).
Pliocene. — San Pedro (Arnold).
254. Trophon (Boreotrophon) stuarti Sviiih.
V\..\TK VI, Fic. 4.
Trophon shiarli Smith, Proc. Zool. Soc, 1S80, p. 481, PI. XLVIII, fig. 6.
Trophon orpheiis Old., Cpr., Brit. Assn Rept., 1863, p. 663 (in part). Trvon, Man. Conch.,
Vol. II, p. 139, PI. XXXI, fig. 310, 1880 (in part). Cooper, 7th Ann. Rept. Cal. St.
Min., 1888, p. 268 (in part). Keep, West Coast Shells, p. 21, 1892 (in part).
Shell of medium size, fusiform; spire elevated, acute; whorls seven, sharply angular, crossed
by nine to eleven frill-like varices which rise to sharp points on angle; whorls ornamented with two
to three sharp, spiral ridges, one of which revolves on angle; aperture semielliptical; outer lip
thickened, smooth within; inner lip incrusted, projecting; columella long, twisted, squamose; canal
long, narrow, slightly curved.
Dimensions. — Long. 30 mm.; lat. 13 mm.; body-wliorl 2 mm.; aperture, including canal
16.5 mm.; canal 8 mm.; defl. 52 degrees.
Distinguishable by prominent, frill-like varices and sharp spiral lines, which
give latticed appearance. Specimens identified by Dr. Dall.
ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 253
Rare in Pliocene of Deadman Island and Tiniin's Point; also reported from
lower San Pedro series at Deadman Island. The specimen figured is from the
Pliocene at Deadman Island, and is now in the collection of Delos Arnold.
Living. — Sitka to Straits of Fuca; Washington (Cooper).
Pleistocene. — San Pedro; San Diego (Cooper): San Pedro (Arnold).
Pliocene. — San Pedro (Arnold): San Diego well (Dall).
255. Trophon (Boreotrophon) stuarti Smith var. praecursor, var. nov.
Plate VI, Fig. 5.
Shell small, elongate-fusiform; spire elevated, acute; whorls six or seven, angulated above,
crossed by about fifteen sharp varices, and with two sharp spiral lines; suture deeply impressed
distinct; aperture subelliptical; outer lip effuse, smooth; inner lip smooth; columella long, straight,
nearly smooth; canal long, narrow, very slightly curved.
Dimensions. — Long. 15 mm.; lat. 5.5 mm.; body-whorl 10 mm.; aperture, including canal,
8 mm.; canal 4.2 mm.; defl. 35 degrees.
Distingnishable from T. »tuarti by smaller .size, le.ss prominent transverse
frills and spiral lines, and slenderer form; distingni.shable from T. ditiparilis by much
more sharply defined sculpture and more angulated whorls. Pronounced var. jjrre-
cursor of 7\ studiil by Dr. Dall. Type from Pliocene of Deadman Island.
Not uncommon in Pliocene and lower San Pedro series of Deadman Island.
Found also in Pleistocene at bath-house, Santa Barbara. The specimen figured is
the type, which was found in the Pliocene of Deadman Island, and is now in the
collection of Delos Arnold.
Pleistocene. — San Pedro (Arnold).
Pliocene. — San Pedro; Santa Barbara (Arnold).
256. Trophon (Boreotrophon) tenuisculptus Carpenter.
Trophon teimisculptus Cpr., Ann. & Mag. Nat. Hist., 3rd Ser., Vol. XVII, 1866, p. 277. Gabb, Pal.
Cal., Vol. II, p. 70, 1869. Trvon, Man. Conch., Vol. II, p. 139, PI. XXXIII, fig. 359,
1880. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 268.
Shell small, fusiform; whorls five, angulated above, forming a slightly sloping, tabular band
above; ornamentations of numerous transverse ridges and several spiral lines; suture deeply
impressed; aperture elliptical; outer lip thin; inner lip incrusted, smooth; canal narrow; columella
long, twisted.
Dimensions of a Young Specimen. — Long. 14.5 mm.; lat. 6.1 mm.; body-whorl 10 mm.;
aperture and canal 8 mm.; canal 4.5 mm. ; defl. 50 degrees.
Distinguishable by numerous transverse ridges, which are more numerous
than in any other member of this genus found in this locality. Type of species
from Pleistocene of Santa Barbara. Specimen identified by Dr. Dall.
Rare in Pliocene of San Pedro district.
Pleistocene. — Santa Barbara (Carpenter).
Pliocene. — San Pedro (Arnold).
254 CALIFOUNIA ACADEMY OF SCIENCES.
257. Trophon (Boreotrophon) triangulatus Citrpenter.
Trop/ion /rnt//g7(/a///s Cfr., Brit. Assn. Rept., 1863, p. 663; Proc. Cal. Acad. Sci., Vol. Ill, 1865,
p. 224. Trvon, Man. Clinch., Vol. II, p 42. 1880. Cooper, 7th Ann. Rept. Cal. St.
Min., 1888, p. 268.
Trophon ( Doreoirophmi) Iriangii/atiis Cpr., Dall, Proc. U. S. Nat. Mus., V^ol. XIV, 1891, p. 180,
PI. V, figs. I, 3 and 6; Vol. XV, 1892, p. 216.
" Whorls about seven, the nuclear lost; varices six to the whorl, strong, wide, thin-edged,
with guttered spines which have their hinder edge rounded; surface with strongly marked lines of
growth and half obsolete, fine, irregular, spiral scratches, strongest on the body and almost wholly
wanting between the suture and the spines; the aperture in some specimens might be denticulate.
"Dimens707is. — Long. 75 mm.; lat. 50 mm.; aperiure 56 mm."
As the only shell foiiiul in the Pleistocene was an extremely yonng and worn
specimen, the above, taken from a description by Dr. Dall (Proc. U. S. jSTat. Mus.,
Vol. XIV, p. 180), is inserted. The Pleistocene specimen measures 9 ram. in
length, and has nine varices. The yonng of this species is distinguishable fi'om the
young of T. grafi/is by having a shorter canal and less prominent varices.
Rare in lower San Pedro series of Deadman Island.
Living. — Santa Cruz Island to Catalina; Lower California (Cooper): San
Pedro (Williamson).
Pleistocene. — Santa Baibara (Coopei'): Sail J-'edru (Ainuld).
Genus Ocinebra Leach.
Shell small, \\ ith numerous varices which are foliated and often s]iinose; spiral sculpture;
canal more or less closed.
Ocinebra erinaceus Linn, is a characteristic species.
258. Ocinebra barbarensis Uabb.
Plate V, Fio. 1.
Murex baibarcmis, Gabb, Proc. Cal. Acad. Sci., Vol. Ill, 1865, p. 183.
Muricidea barbarensis Gabb, Pal. Cal., Vol. II, p. 69. 1869.
Ocinebra barbarensis Gabb, Trvon, Man. Conch., Vol. II, p. 124, 1880.
Shell small, fusiform; spire elevated, subacute; whorls four or five, sharply angulated, flat
or concave above, slightly convex below, ornamented with five to nine rather sharp, transverse
ridges, which rise to a sharp, recurved process on angle, and by numerous strong, squamose, revolv-
ing ridges; suture very deeply appressed, giving spire a staircase appearance; aperture subelliptical;
outer lip thickened, denticulated; inner lip incrusted, projecting slightly; canal short, narrow, gener-
ally covered; columella slightly widened and twisted.
Dimensions. — Long. 19mm.; lat. 10 mm.; body-whorl 15 mm.; aperture, inckuiing canal,
II mm.; canal 5 mm.; defl. 60 degrees.
Distinguishable from O.perita by more prominent processes on angle of whorl,
more prominent spiral ridges, deeper appressed suture, and more tabulated upper
portion of whorl. Specimens identified by Dr. Dall.
ARNOLD— THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 255
Rare in the lower San Pedro series at Pan Pedro and Deadmaii Island.
Found also in the Pleistocene at Santa Barbara. The specimen figured is from
the lower San Pedro series at Deadman Lsland, and is now in the collection of
Delos Arnold.
Living. — Catalina Island; Santa Baibara Channel (Cooper).
Pleistocene. — Santa Barbara (Gabb; Arnold): San Pedro (Arnold).
259. Ocinebra foveolata Hinds.
Murcx foveolala Hds., Proc. Zool. Soc, 1S43, P- '-71 Voyage Sulphur, p. 9, No. 13, PI. III. tigs.
15, 16, 1S44. Cpr., Brit. A.ssn. Rept., 1856, p. 205. Tryon, Man. Conch., Vol. II,
p. 125, PI. XXXVIII, tig. 465, 1880.
Mjoicidea foveolala Hds., CoopiiR, 7th Ann. Rept. Cal. St. Min., 1888, p. 252.
Ocinebra foveolata Hds., Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 215.
Shell of medium size, fusiform; spire elevated; whorls six, angulated, with six or seven
prominent, rounded, transverse ribs that rise to the prominence of nodes on the angle of the whorl;
surface ornamented with numerous clear-cut, rather squarish, raised lines, and incremental lirulae in
the interspaces; suture deeply appressed, wavy; aperture subpyriform; outer lip thickened, denticu-
lated; inner lip incrusted, smooth; canal long, narrow, slightly curved; columella not perceptibly
widened; umbilicus subperforate.
Dimensions. — Long. 35 mm.; lat. 17 mm.; body-whorl 28 mm.; aperture, including canal,
20 mm.; canal g mm.; defl. 60 degrees.
Distinguishable by the broad, prominent, transverse ridges which rise to
rounded nodes rather than to sharp points, as in some other members of the genus,
and by the deep suture and lather long, narrow form of the shell. Specimen identi-
fied by Dr. Dall. Specimens of 0. periia in the State Museum collection of fossils at
Berkeley are labeled ''0. foveolata."
Rare in upper San Pedro series of San Pedro; one imperfect specimen found.
Living. — Baulinas Bay to Lower California (Cooper).
Pleistocene. — Santa Barbara; San Pedro (Cooper): San Pedro (Arnold).
260. Ocinebra interfossa Carpenter.
Ocinebra interfossa CpR., Brit. Assn. Rept., 1863, p. 663. Gabb, Pal. Cal., Vol. II, p. 70, 1869.
Tryon, Man. Conch., Vol. II, p. 131, PI. XXXIX, fig. 484, 1880. Cooper, 7th Ann.
Rept. Cal. St. Min., 1888, p. 254. Keep, West Coast Shells, p. 24, fig. 5, 1892.
Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 215.
Shell small, broadly fusiform; spire elevated, subacute; whorls five or six, angulated above;
surface sculptured with numerous transverse and spiral ridges of nearly equal prominence, giving the
surface a latticed appearance; suture deeply impressed, distinct; aperture subovate; outer lip
thickened, slightly denticulated; inner lip smooth, incrusted; canal short, generally covered;
columella twisted, squamose; umbilicus subperforate.
Dimensions. — Long. 13 mm.; lat. 7.2 mm.; body-whorl 10 mm.; aperture, including canal,
7 5 mm.; canal 2.5 mm.; defl. 55 degrees.
Distinguishable from other members of genus by strong, latticed sculpture,
short canal and small size. Identified by Dr. Dall.
256 CALIFORNIA ACADEMY OF SCIENCES.
JRather common in upper San Pedro series at San Pedro; one in Pliocene at
Deadman Island; found also in Lower San Pedro series at Deadman Island and San
Pedro, and in the npper San Pedro series at Crawfish George's and Deadman Island.
Found also in the Pleistocene at Pacific Beach, San Diego.
Living. — Sitka to San Diego (Cooper).
Pleistocene. — Santa Barbara (Cooper): San Pedro; San Diego (Arnold).
Pliocene. — San Pedro (Arnold).
261. Ocinebra keepi, sp. nov.
Plate V, Fig. 9.
Shell of medium size, fusiform; spire elevated, subacute; whorls five to six, strongly angu-
lated above, giving a tabulate appearance to upper portion; whorls crossed by about seven sharp
frills, which flex forward, and rise to prominent points on the angle; anterior portion of whorl
ornamented with five or six strong, rough, subangular spiral lines, more prominent on lower
portion of whorl; posterior portion of whorl smooth between frills, except near suture, where the
surlace is roughened by laminated, incremental lines; suture deeply appressed, undulating, distinct;
aperture subelliptical; outer lip thickened and slightly denticulated; inner lip enameled, slightly
projecting; columella twisted, squamosa, only slightly widened; umbilicus subperforate; canal of
medium length, narrow, sometimes covered with overgrowing lips.
Dhnensions. — Long. 35.5 mm.; alt. 21 mm.; body-whorl 26.5 mm.; aperture 20 mm.; canal
7.5 mm.; defl. 56 degrees.
Distinguishable from other members of the genus by the transverse frills.
The type specimen shows the original reddish brown color. Pronounced a new
species by Dr. Dall. Named in honor of Professor Josiali Keep of Mills College,
who has done so much toward advancing the study of conchology on the Pacific Coast.
Rare in upper San Pedro series at San Pedro; type specimen found at Dead-
man Island in the upper San Pedro conglomerate. The si^ecimen figured is the
type, which is now in the United States National Museum. One specimen from the
upper San Pedro series at the lumber yard, San Pedro.
Fleisiocene. — San Pedro (Arnold).
262. Ocinebra lurida Middendorf .
Tritonium tnridum Midd., Mai. Ross., PI. il., p. 150, PI. IV., figs. 4, 5, 1849.
Ocinebra lurida Midd., Cpr., Brit. Assn. Re|)t., 1863, p. 663. Gabb, Pal. Cal. , Vol. II., |). 70, 1869.
Trvon, Man. Conch., Vol II , p. 131, PI. XXXIX, figs. 481, 4S5, 1888. Keep, West
Coast Shells, p. 23, fig. 4, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV,
1892, p. 215, PI. XX, fig. 3.
Shell of medium size, fusiform; whorls six, convex, slightly angulatcd near posterior margin;
upper whorls with several transverse ridges; surface ornamented with numerous rounded, raised
lines; suture deeply impressed, distinct; body-whorl not extraordinaril yventricose; aperture sub-
ovate; outer lip thickened, denticulated; inner lip incrusted; columella widened; umbilicus subper-
forate; canal narrow, sometimes covered with overgrowing lips.
Dimeyisions. — Long. 25 mm.; lat. 13.3 mm.; defl. 55 degrees.
AKNOLD — THE PALEONTOLOGY AND STRATIGKAPHY OF SAN PEDRO. 257
Distinguishable by lack of transverse I'idges of any kind on body-whorl and
its antecedent whorl. Specimen identified by Dr. Dall.
Rare in upper San Pedro series of San Pedro; one deformed specimen from
Crawfish George's. Found in Pleistocene at Pacific Beach, San Diego.
Living.— Sitka to Santa Barbara (Cooper): San Pedro (U. S. Nat. Mus.).
Pkistocene. — San Pedro; San Diego (Arnold).
263. Ocinebra lurida MidcL, var. aspera Baird.
Plate V, Fig. 12.
Vilularia aspera Baird, Proc. Zool. Soc, 1863, p. 66.
Ociiicha lurida v2lx. aspera Baird, Cpr., Brit. Assn. Rept., 1863, p. 663. Tryon, Man. Conch.,
Vol. II, p. 131, 1880. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 254.
Shell of medium size, fusiform; whorls six, convex, with about nine prominent, rounded
transverse ribs; surface ornamented with numerous rounded, raised, spiral lines and fine incremental
lirulas in the interspaces; suture deeply impressed, distinct; body-whorl prominently ventricose, and
with transverse, rounded ridges which become obsolete on columella; aperture subovate; outer lip
thickened, denticulated; inner lip slightly flattened, incrusted; columella only slightly widened;
umbilicus subperforate; canal straight, narrow.
Dimensions. — Long. 27 mm.; lat. 14 mm.; body-whorl 20 mm.; aperture, including canal,
16 mm., canal 6 mm.; defl. 55 degrees.
Distinguishable from 0. lurida by more ventricose body-whorl, and by the
rounded ridges on the lower whorls, which are lacking in lurida. Specimens
identified by Dr. Dall.
Rather common in the upper San Pedro series at San Pedro, Los Cerritos,
Crawfish George's and Deadman Island; also found in the lower San Pedro series at
Deadman Island and San Pedro. Found in the Pleistocene at bath-house, Santa
Barbara; and irrigating ditch, Ventura. The specimen figured is from the upper
San Pedro series at San Pedro, and is now in the collection of Delos Arnold.
Living. — Sitka to Santa Barbara (Cooiaer).
Pleistocene. — Santa Barbara; San Pedro (Cooper): San Pedro (Arnold).
264. Ocinebra lurida Midd., var. cancellina Philippi.
Platk IX, Fig. 11.
Fusus cancelliyncs Phil., Archiv. fiir Naturg, Bd. I, 1845, p. 67; Abbild., II, Fusus, PI. Ill, fig. 2.
Urosalpinx ca7icellinus Phil., Tryon, Man. Conch., Vol. II, p. 154, PI. XXXIX, fig. 492, 1880.
Shell small, broadly fusiform; spire elevated, subacute; whorls four, convex; body-whorl
ventricose; whorls crossed by about nine prominent, broad, rounded ribs, the interspaces ornamented
with prominent rounded, raised spiral lines, between which are numerous squamose incremental
lirulae; suture not deeply impressed, rather indistinct, undulating; aperture subelliptical; outer lip
slightly twisted, squamose, not widened; canal short, rather broad, uncovered; umbilicus subperforate.
Ditnensiotis. — Long. 22 mm.; lat. 12.5 mm.; aperture 12.5 mm.; canal 4 mm. ; defl. 62 degrees.
( 33 ) March 26, 1903.
258 CALIFOKNIA ACADEMY OF SCIENCES.
Distinguishable by broad and depressed form, broad, rounded ridges, and
prominence of the spiral lines and incremental liruhe. Specimen identified by
Dr. Dall.
Rare in upper San Pedro series at San Pedro. The specimen figured is
from the upper San Pedro series at San Pedro, and is now in the United States
National Museum.
Living. — Straits of Magellan (Tryon).
Pleistocene. — San Pedro (Arnold).
265. Ocinebra lurida Midd., var. cerritensis, var. nov.
Plate V, Fig. 5.
Shell .small, broadly fusiform, heavy; spire elevated, subacute; whorls four, convex, enlarging
rapidly from the first whorl; body-whorl ventricose; whorls crossed by about nine prominent, rather
narrow, rounded ribs, which extend to end of columella; interspaces ornamented with strong, raised,
spiral lines; suture impressed, not very distinct; aperture subelliptical; outer lip thickened, with a
row of about six prominent denticles; inner lip smooth, incrusted; columella not much widened,
abruptly truncated at end; umbilicus subperforate; canal short, straight, narrow.
Dimensio7is. — Long. 17 mm.; lat. 10 mm.; body-whorl 14.5 mm.; aperture ii mm.; canal
3 mm.; defl. 60 degrees.
Distinguishable from others of its genus by large body-whorl, depressed
appearance, small size and heavy shell. Pronounced a new variety by Dr. Dall.
Rare in upper San Pedro series of the San Pedro region; first found at Los
Cerritos; type from Crawfish George's; also found in the lower San Pedro series at
Deadman Island and San Pedro. The specimen figured is the type, which is now in
the United States National Museum.
Pleistocene. — San Pedro (Arnold).
266. Ocinebra lurida Midd., var. munda Carpenter.
Ocinebra lurida V2X. munda Cpr., Brit. Assn. Rept. , 1863, p. 663. Dall, Proc. U. S. Nat. Mus. ,
Vol. XV, 1892, p. 215, PI. XX, fig. 3.
Shell small, fusiform, thick, solid; spire elevated, apex acute; whorls five or six, evenly
convex; sculpture consists of rather low, rounded, transverse ridges (of which there are about twelve
on the penultimate whorl) and equal, equidistant, rounded, raised, spiral lines (of which there are
six on the penultimate whorl); suture quite deeply impressed; aperture elliptical; outer lip tlnck-
ened with row of denticles interiorly; inner lip and columella smooth; canal short, narrow,
generally covered.
Dimensions. — Long. 14 mm.; lat. 6.5 mm.; body-whorl 10 mm.; aperture, including canal,
7.5 mm.; canal 2.5 mm.
Distinguishable from others of the genus by its low, rounded, transverse ribs,
which are of the same size and prominence from suture to suture, regular spiral lines
ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 259
and slender shape. The sculpture of this species is less prominent than on the other
species of this genus.
Several specimens from the lower San Pedro series of Deadman Island.
Living. — Catalina Island (Dall).
Pleistocene. — San Pedro (Arnold).
267. Ocinebra micheli Ford.
Plate V, Fig. 15.
Shell small, elongate-fusiform; spire elevated, acute; whorls five or si.\, strongly angulated
above, crossed by about nine prominent, rather sharp ridges, which are most prominent on angle;
anterior portion of whorl with four or five strong, squamose, raised lines, between which are numerous
squamosa, incremental lirulae; suture deeply appressed, distinct; aperture subovate; outer lip thick-
ened, smooth interiorly; inner lip incrusted, slightly raised; columella long, twisted, squamose; canal
long, narrow, nearly covered.
Dhnensions. — Long. 16 mm.; lat. 7 mm.; body-whorl 11 mm.; aperture, including canal,
8.5 mm.; canal 4 mm.; defl. 40 degrees.
Re.sembles 0. perita somewhat, but is distinguishable by more slender form,
longer columella, and greater number of transverse ridges. Identified by Dr. Dall.
One sj^ecimen from the upper San Pedro series at Crawfish George's, which is
figured, and is now in the collection of Delos Arnold.
Living. — West Coast North America.
Pleistocene. — San Pedro (Arnold).
268. Ocinebra perita Hinds.
Murex peritus Hds., Proc. Zool. Soc, 1S43, p. 129; Voyage Sulphur, p. 9, PI. Ill, figs. 23, 24, 1844.
Ocinebra perita Hds., Tryon, Man. Conch., Vol. II, p. 124, 1880.
Muricidea perita Hds., Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 252.
Shell of medium size, fusiform; whorls five, sharply angulated, with about six or seven rather
sharp, transverse ridges which are most prominent on angle; surface ornamented with numerous
raised lines, with squamose, incremental lirulae in the interspaces; suture deeply appressed, wavy;
aperture subovate; outer lip thickened, denticulated; inner lip smooth, incrusted; canal long,
straight, narrow, sometimes covered; columella somewhat twisted, slightly widened; umbilicus
subperforate.
Dimensions. — Long. 24 mm.; lat. 12.5 mm.; body-whorl 17 mm.; aperture, including canal
14 mm.; canal 6 mm.; defl. 60 degrees.
Distinguishable from 0. harharensis by less prominent points on angle of whorl,
and by less prominent spiral lines. Identified by Dr. Dall as probably 0. perita.
Several specimens labeled by Dr. Dall as "0. interfossa, leaning toward
0. peinta" had about one more transverse rib to the whorl than does the typical
0. perita, the ribs were not so prominent on the angle, but the spiral lines were
stronger than in the latter species. Comparing a series of both forms they are seen
260 CALIFOKNIA ACADEMY OF SCIENCES.
to intergrade, and they do not vary enougli to justify making a variety out of the
new form.
Found in the lower San Pedro series at Deadman Island; and in the upper
San Pedro series at Deadman Island, San Pedro, and Crawfish George's. Found in
the Pleistocene at bath-house, Santa Barbara; and Pacific Beach, San Diego.
Living. — Santa Barbara to Lower California (Cooper).
Pleistocene. — Santa Barbara (Cooper; Arnold) : San Pedro; San Diego (Arnold).
269. Ocinebra poulsoni Kuttall.
Plate V, Fig. 2.
Ocinebra pouhoni NuTT., Cpr., Brit. Assn. Rept., 1863, p. 663. Nuttall, mss., Cpr., Jour,
de Conch., Vol. XII, 1865, p. 148. Tryon, Man. Conch., Vol. II, p. 130, PI.
XXXVIII, fig. 475, 1880. Keep, West Coast Shells, p. 23, 1892. Williamson, Proc.
U. S. Nat. Mus., Vol. XV, 1892, p. 215. Cooper, Bull. No. 4, Cal. St. Min. Bureau,
Part 3, 1894, p. 30.
Shell of medium size, elongate-fusiform; spire elevated, compact; whorls six, deeply concave
above, convex below, with rounded transverse ridges rising to prominent nodes on angle of lower part
of whorl; nuclear whorls coarsely cancellated; ridges obsolete on concave portion of whorl; more or
less prominent spiral ridges on lower portion of whorl; spiral sculpture faint on concave surface; fine
incremental lines quite prominent; suture not deeply appressed, wavy; aperture semielliptical;
outer lip denticulated; inner lip effuse, incrusted, smooth; canal short, narrow; columella slightly
twisted, widened; umbilicus subperforate.
Dimensions. — Long. 32 mm.; lat. 16.5 mm.; body-whorl 23 mm.; aperture 16 mm.; canal
5 mm. ; defl. 42 degrees.
The specimen described is a narrow form, some of the specimens showing a
deflection of 55 degrees. Many of the specimens retain the coloration of the brown
spiral bands. Specimens identified by Dr. Dall.
Rare in lower San Pedro series at Deadman Island and San Pedro; not
uncommon in upper San Pedro series at San Pedro, Los Cerritos, Crawfish George's,
and Deadman Island. Found also in the Pleistocene at Twenty-sixth Street, San
Diego. The specimen figured is from the upper San Pedro series at San Pedro, and
is now in the collection of Delos Arnold.
Living. — Santa Barbara to San Diego (Cooper): Lower California (Carpenter).
Pleistocene. — ^Ventura (Bowers): San Pedro; San Diego (Arnold).
Subfamily PURPURINjE.
Genus Purpura Bruguiere.
Shell oblong-oval, last whorl large; spire generally short; aperture ovate, large, terminating
in a very short oblique channel, or notched; columella flattened; outer lip simple.
Purpura persica Linne is a typical species.
AENOLD — THE PALEONTOLOGY AND STEATIGKAPHY OF SAN PEDEO. 261
270. Purpura crispata Chemnitz.
Purpura crispata Chem., Conch. Cab., XI, PI. 187, figs. 1802 and 1803, 1795; Kuster, Conch. Cab.,
p. 105, PI. XIX, figs. 3 and 4, 1837. Cpk., Brit. Assn. Rept, 1863, P- 662. Tryon,
Man. Conch., Vol, II, p. 175, PI. LXIII, figs. 163-166, 168, 1880. Cooper, 7th Ann.
Rept. Cal. St. Min., 1888, p. 261. Keep, West Coast Shells, p. 33, fig. 13, 1892.
Shell fiasiform, thick; spire elevated; apex subacute; whorls five to seven, convex or
angulated, with one or more prominent spiral ridges on angular part of whorl; suture impressed,
distinct; aperture ovate to elliptical; outer lip effuse, generally denticulate; inner lip incrusted,
smooth; canal short, curved backwards; umbilicus subperforate.
Dwiensions. — Long. 34 mm.; lat. 20 mm.; body-whorl 26 mm.; aperture, including canal,
22.5 mm.; canal 6 mm.; defl. 55 degrees.
The specimen whose dimensions are given was a small one, but the relative
proportions in this specimen seemed to be about the average. A very variable species,
some being nearly smooth and some almost spinous in their roughness. The smooth
forms generally lack the denticulation of the outer lip. The shell texture is very
well preserved in most of the Pleistocene specimens, some of them being almost
indistinguishable from living shells.
Not common in the upper San Pedro series of San Pedro, Deadman Island,
and Crawfish George's. Found in the Pliocene at Pacific Beach and Russ School,
San Diego.
Living. — Sitka to Santa Barbara (Cooper).
Pleistocene. — Santa Barbara to San Diego (Cooper): San Pedro (Arnold).
Pliocene. — Seven Mile Beach, San Mateo County (Cooper) : San Diego (Arnold).
271. Purpura saxicola Valenciennes.
Purpura saxicola Val., Venus, PI. VIII, fig. 4, 1846. Cpr., Brit. Assn. Rept., 1863, p. 662,
^=P. lapillus Cooper (not Linn, sp., Lam.), Gabb, Pal. Cal., Vol. II, p. 75, 1869.
Tryon, Man. Conch., Vol. II, p. 174, PI. LIII, figs. 152, 154a, 18S0. Cooper, 7th
Ann. Rept. Cal. St. Min., 1888, p. 262. Keep, West Coast Shells, p. 31, fig. 11, 1892.
Shell small, semiglobular; spire slightly elevated; apex subacute; whorls four, angulated,
tabular on top; body-whorl ventricose; surface ornamented with obsolete spiral ridges and fine
incremental lines; suture impressed, distinct; aperture large, elliptical; outer lip smooth, thin, effuse;
inner lip and columella flattened, incrusted, sharp; canal short.
Dimensions. — Long. 18 mm.; lat. 13 mm.; aperture, including canal, 16 mm.; canal
13.5 mm.; defl. 85 degrees.
Quite a variable form. All the Pleistocene specimens at hand show the
mottled or banded reddish brown coloration. Distinguishable from P. crkpata by
the small spire, large body-whorl, large aperture, and smoothness of the shell.
Rare in upper San Pedro series of San Pedro; three specimens. Found in
the Pleistocene at irrigating ditch, Ventura.
Living. — Alaska to San Diego; Lower California (Cooper).
262 CALIFORNIA ACADEMY OF SCIENCES.
Fleistocem. — Santa Barbara; San Pedro; Ventura (Arnold).
Pliocene. — Santa Rosa; Kirker's Pass; San Fernando (Cooper): Stanford
University (Arnold).
Subfamily CORALLIOPHILIN^.
Genus Coralliophila H. tC- A. Adams.
Shell broadly fusiform; nuclear whorls smooth; postnuclear whorls with rasp-like surface,
and somewhat open umbilicus.
Coralliophila neritoidea is a characteristic species.
272. Coralliophila nux Reeve.
Murex nux RvE., Conch. Icon., sp. 81.
Coralliophila nux RvE., Tryon, Man. Conch., Vol. II, p. 210, PI. LXVI, figs. 368, 374, 1880.
Shell purpuroid shaped; whorls angular; surface rough and cancellated by spiral and trans-
verse squamose ridges, the spiral ridges being the most prominent; suture deep. Longitude about
12 millimeters.
This specimen is too imperfect to allow of a good description. Dr. Dall
labeled this specimen "Corallio'pliila, probably var. of nux."
One specimen from the upjier San Pedro series of San Pedro.
Living. — Mazatlan to Panama; Gallapagos Islands (Tryon).
Pleistocene. — San Pedro (Arnold).
Suborder STREPTOD ON T A.
Superfamily PTENOGLOSSA.
Family LXII. SCALIDyE.
Genus Scala Hum^ihrey.
Shell mostly pure white and lustrous; turreted, many whorled; whorls round, sometimes
separated, ornamented with numerous transverse ribs; aperture round; peristome continuous.
Scala pretiosa Linn, is a characteristic species.
ARNOLD — THE PALEONTOLOGY AND STEATIGKAPHY OF SAN PEDRO. 263
273. Scala bellastriata Carpenter.
Plate IX, Fig. 17.
Scalaria bellastriala CvR., Brit. Assn. Rept., 1863, p. 660; Proc. Cal. Acad. Sci. , Vol. Ill, 1864,
p. 22. Gabb, Pal. Cal., Vol. II, p. 78, 1869. Cooper, 7th Ann. Rept. Cal. St. Min.,
1888, p. 263.
Scala bellastriata Cpr., Williamson, Proc. U, S. Nat. Mus., Vol. XV, 1892, p. 209.
Shell conical, with elevated spire; whorls six, rounded, each having fifteen thin varices;
suture almost separating whorls; varices spinous at shoulder, a few of the varices thickened; inter-
varical spaces ornamented with spiral ridges; aperture slightly elliptical, with longer axis vertical.
Dimensions. — Alt. 17.5 mm.; lat. 10 mm.; defl. 42 degrees.
This species is easily distinguishable by its low sjiire and by its sjiiral orna-
mentation. The only other member of this genus found in this locality which has
sj^iral sculpture is S. liemphilli, which has a much slenderer spire and a less im-
pressed suture. The figure of this species is of a living shell from San Pedro, which
is now in the collection of Delos Arnold.
Rare; only four found in the upper San Pedro series of San Pedro.
Living. — San Pedro to San Diego (Cooper).
Pleistocene. — Santa Barbara (Cooper): San Pedro (Arnold).
274. Scala crebricostata Carpenter.
Scalaria crebricostata Cpr., Brit. Assn. Rept., 1863, p. 660; Proc. Cal. Acad. Sci., Vol. Ill, 1864,
p. 222. Gabb, Pal. Cal., Vol. II, p. 78, 1S69. Cooper, 7th Ann. Rept. Cal. St. Min.,
1888, p. 263.
Shell turreted, thin; spire consists of eight convex whorls, each with fourteen to eighteen
slightly oblique, sharp, thin, reflexed, transverse varices; varices show a slightly coronate appearance
at the shoulder; suture deep and distinct. Deflection 22 degrees.
Some of the specimens have only slightly reflexed varices, and the amount of coronation
varies in different individuals.
Distinguishable from 8. indianoricm by thinner shell, thinner and sharper
varices, and more impressed suture; distinguishable from S. tinda by more numerous,
and generally more reflexed varices; distinguishable from 8. hindsii by more numer-
ous and less coronated varices. Specimens identified as questionable by Dr. Dall.
Rare in the upper San Pedro series at San Pedro and Deadman Island; also
in lower San Pedro series at San Pedro. Found in the Pleistocene at Barlow's ranch
and irrigating ditch, Ventura; and at Twenty-sixth Street, San Diego.
Living. — Monterey to San Diego (Cooper).
Pleistocene. — Santa Barbara; San Pedro (Cooper): San Pedro; Ventura; San
Diego (Arnold).
264 CALIFOKNIA ACADEMY OF SCIENCES.
275. Scala hemphilli Dull.
Scala hemphilli Dall, Proc. U. S. Nat. Mus., Vol. I, 187S, p. 16. Cooper, 7th Ann. Rept. Cal.
St. Min., 1888, p. 263.
Shell resembling robust 3". iincia; nine to twelve varices, coronated behind near suture:
surface of whorls beneath the varices longitudinally delicately sculptured with alternate grooves and
riblets. Deflection 30 degrees.
Distinguishable from S. lellastriata by less prominent spiral sculpture and by
a less deflection; from other members of the genus found here by its deflection and
the spiral sculpture. . The specimen described was identified by Dr. Dall.
One immature specimen from the upper San Pedro series of San Pedro.
Pleistocene. — San Diego (Dall): San Pedro (Arnold).
Pliocene. — San Diego well (Dall).
276. Scala hindsii Carpenter.
Scalaria hindsii CpR., Proc. Zool. Soc, 1856, p. 165; Brit. Assn. Rept., 1856, p. 336; 1863, p. 660.
Keep, West Coast Shells, p. 49, fig. 31, 1892, =5". subcoronata Cpr., i^fide Cooper, Bull.
No. 4, Cal. St. Min. Bureau, Part 3, 1894, P- 3^)-
Scala hindsii Cpr., Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 209.
Shell small, turreted, thin; whorls eight, evenly convex; varices eight to twelve, sharp, thin,
sometimes reflexed, very prominently coronated just anterior to suture; suture deep, distinct; aperture
subcircular; lip slightly thickened; inner lip slightly incrusted.
Dimensio7is. — Long. 11.5 mm.; lat. 5.2 mm.; defl. 27 degrees.
Distinguishable from 8. indianorum by smaller and thinner shell, fewer,
thinner, and more coronated varices, and deeper suture; distinguishable from
S. iincta by smaller shell, and fewer and more coronate varices; distinguishable from
8. crebricost((ta by fewer and more coronate varices. Several specimens were identified
by Dr. Dall.
Rare in upper San Pedro series at San Pedro, Deadman Island, Crawfish
George's, and Los Cerritos; also reported from lower San Pedro series at Deadman
Island and San Pedro.
Living. — Santa Barbara (Jewett): San Pedro (Williamson): Panama
(Carpenter).
Pleistocene. — San Pedro (Arnold).
277. Scala indianorum Carpenter.
Plate V, Fig 4.
Scala indianorum Cpr., Brit. Assn. Rept., 1863, p. 660; Ann. & Mag. Nat. Hist., 3rd Ser., Vol. XV,
1865, p. 31. Tryon, Man. Conch., Vol. IX, p. 70, PL XIV, fig. 48, 1887. Cooper,
7th Ann. Rept. Cal. St. Min., 1888, p. 263. Keep, West Coast Shells, p. 50, 1892.
Scala indianonwi Cpr., Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 210.
ARNOLD — THE PALEONTOLOGY AND STKATIGEAPHY OF SAN PEDRO. 265
Shell thick, elongated; spire elevated; apex acute; whoils ten, rounded, with twelve to
sixteen heavy, reflexed varices; varices striated with fine incremental lines; suture deep; aperture
subcircular; inner lip thickened, forming columella.
Dimetisions. — Long. 26.5 mm.; lat. 9 mm.; defl. 32 degrees.
Distinguishable from *S'. tincta by heavier shell, thicker and generally more
numerous varices, which are reflexed, and by a more .solid appearance caused by the
less sunken suture; distinguishable from S. himhii by more whorls, thicker shell,
more varices, which are thicker, more reflexed and less coronate, and by less promi-
nent sutures; distinguishable from S. crebricostata by thicker shell, thicker varices,
which are more reflexed, and by a less prominent suture. Several specimens of
this species were identified by Dr. Dall.
Two from the Pliocene of Deadman Island; common in the lower and upper
San Pedro series of San Pedro and vicinity. The specimen figured is from the
upper San Pedro series at San Pedro, and is now in the collection of Delos Arnold.
Living. — Straits of Fuca to San Diego (Cooper).
Pleistocene. — Santa Barbara (Cooper): San Diego (Dall): San Pedro (Arnold).
Pliocene. — San Pedro (Arnold).
278. Scala tincta Carpenter.
Plate V, Fig. 3.
Scalaiia iincla Cpr., Brit. Assn. Rept., 1S63, p. 660. Cooper, 7th Ann. Rept. Cal. .St. Min., 1888,
p. 263.
Scalaria indianoriim max. tincta Cpr., Ann. & Mag. Nat. Hist., 3rd Ser. , Vol. XV, 1S65, p. 31.
Tryon, Man. Conch., Vol. IX, p. 70, PI. XIV, fig. 49, 1887.
Shell thin, elongate; spire elevated; apex acute; whorls nine to ten, rounded, with ten to
twelve thin varices, which are generally not reflexed; suture deep; aperture subcircular; inner lip
only slightly thickened.
Dimensions. — Long. 25 mm.; lat. 10 mm.; defl. 28 degrees.
Distinguishable from 8. indianornm by more delicate shell, thinner varices,
which are not reflexed as a rule, thinner lip and much deeper suture; distinguishable
from ti. JiiiuUii by more numerous varices, which lack the distinct coronatioii, and by
more whorls and less deflection; distinguishable from S. crebricostata by fewer and
less reflexed varices. Specimens identified by Dr. Dall.
Rather common in upper, and rare in lower San Pedro series of San Pedro
and vicinity. Found in the Pleistocene at Barlow's ranch, Ventura; at Pacific
Beach and Twenty-sixth Street, San Diego; and in the Pliocene at Pacific Beach
and Russ School, San Diego. The specimen figured is from the upper San Pedro
series at San Pedro, and is now in the collection of Delos Arnold.
Living. — Santa Cruz to San Diego (Cooper).
( 34 ) March 27, 1903.
266 CALIFORNIA ACADEMY OF SCIENCES.
Pleistocene. — San Diego (Cooper): 8an Pedro (Cooper; Arnold): Ventura;
San Diego (Arnold).
Pliocene. — San Diego (Cooper; Arnold).
Genus Opalia H. & A. Adams.
Shell turriculated, imperforate; whorls united, the last with a rib at the base.
Opalia coronata Lam. is a characteristic species.
[S. D.] Opalia anomala Stearns.
Opah'a anofna/a Stearns, Proc. Phil. Acad. Nat. Sci., 1875, p. 464, PL XXVII, fig. i. Cooper,
7th Ann. Rept. Cal. St. Min., 1888, p. 255. Dall, Trans. Wagner Inst. Sci., Vol. Ill,
Part 2, 1892, p. 245.
Shell solid, imperforate, elongated, conical; spire gradually tapering; whorls convex, when
perfect probably eleven to fourteen in number, nearly smooth, being marked only by incremental,
and, in some specimens, by an outgrowth varix; suture well defined; basal whorl traversed spirally
by an inconspicuous rib, varying in prominence, in some specimens barely discernible; the convexity
or angularity of the lower part of the basal whorl modified by the presence or absence of the
basal rib.
Dimensio7is. — Long. 53 mm.; lat. 19 mm.; body-whorl 24.5 mm.; aperture 11 mm.
This large, nearly smooth species has so far been re^wrted only from the
Pliocene of San Diego, where it is quite common.
Pliocene. — San Diego (Hemphill; Stearns; Arnold).
279. Opalia borealis Goidd.
.Sba/arza i5i?rifa/w Gld., Wilkes' Exped., Vol. XII, 1S52, p. 207. Tryon, Man. Conch., Vol. IX,
p. 76, PI. XVI, fig. 89, 1887.
Opalia borealis Gi.T>., Cpr., Brit. Assn. Rept., 1863, p. 660. Cooper, 7th Ann. Rept. Cal. St.
Min., 18S8, p. 255. Keep, West Coast Shells, p. 49, fig. 30, 1892.
Scala (Opalia) borealis CpR., Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 210.
Shell small, turreted, thick; apex generally decollated; whorls seven, only slightly convex;
varices eight, rounded, thick, prominent, and forming radiating ridges from the apex; suture im-
pressed, distinct; body-whorl squarely angulated at base, with keel on angle; base flat, smooth;
aperture subovate; outer lip thin, effuse; inner lip only slightly incrusted.
Dimensions. — Long. 15 mm.; lat, 6 mm.; defl. 22 degrees.
The specimens described were identified by Dr. Dall.
Rare in upper San Pedro series of San Pedro; two specimens.
Living. — Karatschntka; Straits of Fuca to San Diego (Cooper).
Pleistocene. — Santa Barbara (Cooper): San Pedro (Arnold).
ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 267
280. Opalia crenatoides Carpenter, var. insculpta Carpenter.
Opalia (? creyiatoides) var. insadpta CPR., Brit. Assn. Rept. , 1863, p. 660; Ann. & Mag. Nat.
Hist., 3rd Series, Vol. XVII, 1866, p. 277. Cooper, 7th Ann. Rept. Cal. St. Min.,
1888, p. 255.
Shell of medium size, elongated, thick, milk-white; spire elevated, with blunt apex; whorls
six, convex; first and second post-nuclear whorls more convex than the remaining whorls, angulated,
nearly smooth; last four post-nuclear sharply and strongly angulated above, flattened along middle,
and quite abruptly contracted at base; whorls ornamented with twelve to fourteen radiating trans-
verse ribs, which are obsolete on the sides of the whorl, faintly developed at the base, and strongly
developed on the top of the whorl, where they are appressed against the antecedent whorl, and
appear like nodes on the angle of the whorl; a faint sutural riblet is sometimes noticeable on the base
of the whorl; above this sutural riblet are faint holes, corresponding to the intercostal spaces; fine
incremental striations are visible over the whole surface of the shell; the base of the body-whorl, just
below the angle, is ornamented with a prominent, wide, elevated rib; aperture elliptical; outer lip
thickened, rounded, slightly expanded at columella; this lip is finely, concentrically striated; inner
lip rounded, smooth.
Dimensions. — Long. 16.4 mm.; lat. 8.3 mm.; body-whorl 9.9 mm.
This species is distinguishable by its broad form and sharj^ly angular whorls,
which are prominently sculptured above, with obsolete sculpture on the sides of the
whorl. Carpenter's type specimen was a jwst-Pliocene fossil from Santa Barbara.
Rare in the upper San Pedro series at Deadman Island.
Living. — Santa Cruz to Santa Barbara (Cooper).
Pleistocene. — Santa Barbara (Cooper): San Pedro (Arnold).
[S. D.] Opalia varicostata Stearns.
Opalia varicostata Stearns, Proc. Phil. Acad. Nat. Sci., 1875, p. 463, PI. XXVII, figs. 2-5.
Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 255. Dall, Trans. Wagner Inst.
Sci., Vol. Ill, Part 2, 1892, p. 245.
Shell elongated-conical, turreted, tapering, solid, imperforate; aperture ovate; peristome
continuous, thickened; dingy to clear white; suture well defined; whorls united, exceedingly variable
in convexity and altitude; specimens all decollate or truncated, equally solid, though varying in
length from 20 to 60 millimeters, showing four and one-half whorls within the first measurement to
five in the latter; longitudinal ribs nine to twelve, varying in number, prominence and regularity, as
well as in obliquity and thickness; suture more or less waved, dependent upon the prominence of the
ribs, which terminate anteriorly at and join a transverse (spiral) rib at about the middle of the
basal whorl.
Dimeyisions of a Rather Small Specimen. — Long. 34 mm.; lat. 14.5 mm.; body-whorl
17 mm.; aperture 9 mm.
This magnificent but variable species has so far been reported only from the
Pliocene of San Diego, where it is quite common.
Pliocene. — San Diego (Hemphill; Stearns; Arnold).
268 CALIFORNIA ACADEMY OF SCIENCES.
Superfamil}- GYMNOGLOSSA.
Family LXIII. EULIMID.E.
Genus Eulima Risso.
Shell small, white, and polished; slender, elongated with numerous level whorls; spire often
curved to one side; obscurely marked on one side by a series of periodic mouths which form promi-
nent ribs internally; apex acute; aperture oval, pointed above; outer lip tiiickened internally; inner
lip reflected over the pillar, not umbi Heated.
Eulima tortuosa Adams is a characteristic species.
281. Eulima falcata Carpenter.
Plate IX, Fig. 15.
Eulima falcata Cpr., Proc. Zool. Soc, 1865, p. 280.
Shell small, elongated, thin, white, glossy; spire verj' acute, curved into scythe-shape;
whorls ten, flat; suture indistinct, not impressed; body-whorl subangular at base; base elongated;
aperture pyriform, seemingly appressed to side of shell out of its normal position; outer lip acute and
rounding; inner lip concave.
Ditnensions. — Long. 6.5 mm.; lat. 3 mm.; body-whorl 3 mm.; aperture 2.5 mm.; defl.
30 degrees.
Distinguishable from E. jnicans by subangulated body-wliorl, eccentric nperture
and curved spire; distinguishable from E. hastnta by curved spire and more eccentric
aperture. The specimens described were identified by Dr. Dall.
One specimen each from the lower San Pedro series at Deadman Island and
the upper 8an Pedro series at San Pedro. The specimen figured is from the lower
San Pedro series at Deadman Island, and is now in the collection of Delos Arnold.
Living. — Acapulco (Carpenter) .
Pleistocene. — San Pedro (Oldroyd; Arnold).
282. Eulima hastata Sowerby.
Plate IX, Fio. 9.
Eulima hastata Sbv, , Proc. Zool. Soc, 1834, p. 7. Cpr., Brit. Assn. Rept , 1856, p. 335. Tryon,
Man. Conch., Vol. VIII, p. 273, PI. LXIX, t^g. 39, 1886.
Shell small, slender, turreted; apex acute; whorls nine, fiat, smootli; suture indistinct, not
impressed; body-whorl angular below, short; aperture suboval, abruptly truncated in front.
Dimensio7is. — Long. 7.4 mm.; lat. 2.5 mm.; body-whorl 3.1 mm.; aperture 2 mm.; defl.
22 degrees.
Distinguishable by the short, angular base, and short, truncated aperture. In
other respects like E. micans. Specimens identified by Dr. Dall.
Four found in upper San Pedro series at San Pedro; and one in the lower
San Pedro series at Deadman Island. Found in the Pleistocene at Barlow's ranch,
ARNOLD — THE PALEONTOLOGY AND STEATIGKAPHY OF SAN PEDRO. 2G9
Ventura; and at Spanish Bight, San Diego. The specimen figured is from the upper
San Pedro series at San Pedro, and is now in the collection of Delos Arnold.
Living. — Gulf of California; Ecuador (C'arpenter).
Pleistocene. — San Pedro; Ventura; San Diego (Arnold).
283. Eulima micans Carpenter.
Plate IX, Fig. 12.
Eulima micayis Cpr., Brit. Assn. Rept., 1863, p. 659. Reeve, Conch. Icon., p. 33, 1865. Tryon,
Man. Conch., Vol. VIII, p. 272, PI. LXIV, figs. 29, 30, 1886. Cooper, 7th Ann. Rept.
Cal. St. Min., 1888, p. 240. Keep, West Coast Shells, p. 50, fig. 32, 1892. Williamson,
Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 209.
Shell small, turreted, glossy; apex acute; whorls ten, flat; body-whorl convex; suture
distinct, not impressed; aperture elongate-ovate; outer lip thin, rather arcuate; inner lip slightly
incrusted.
Dimensions. — Long. 12 mm.; lat 3.2 mm.; defl. 25 degrees.
Distinguishable from E. falcatn by straight spire and less bulging outer lip;
distinguishable from E. hastata by even convexity of body-whorl. The specimen.s
described were identified by Dr. Dall.
Found in the lower San Pedro series at Deadman Island and San Pedro, and
in the upper San Pedi'o series at Crawfish George's, Los Cerritos, and San Pedro.
The specimen figured is from the lower San Pedro series at Deadman Island, and is
now in the collection of Delos Arnold. Found also in the Pleistocene at Barlow's
ranch, Ventura, and at Spanish Bight, San Diego.
Living. — Straits of Fuca to San Diego (Cooper).
Pkii<iocene. — Santa Barbara to San Diego (Cooper): San Pedro; Ventura;
San Diego (Arnold).
Family LXIV. PYRAMIDELLID^.'
Genus Turbonilla Risso.
Turbonilla Risso, Hist. Nat. Eur. Merid., Vol. IV, p. 224, 1826. Type, Turbonilla typica Dall &
Bartsch, =^Turbonilla pHcatula Risso, 1826, nan Turbo (= Turbonilla ) plicatnlus
Brocchi, 1814.
Shell with sinistral nucleus, slender, having many whorls, with axial ■ or spiral sculpture, or
both; columella straight or twisted, usually with a single fold, which is rarely obsolete; operculum
horny, subspiral, with spiral striae on its outer surface.
Animal with wide, flattened tentacles; mentum elongated, flattened, and bilobed in front;
foot large, short, auriculated anteriorly.
^ The portion of the text relating to this family has been prepared, under the supervision and with the assistance of W. H.
Dall, by Paul Bartsch, aid in the United States National Museum.
-Sculpture following the direction of the coil of the whorls is in these diagnoses referred to as spiral. That at right .ingles to
the spiral sculpture, or in general parallelism with the axis of the shell, is called axial. An endeavor has been made to Include all the
Pleistocene species known from California, some of which, though found at San Diego, have not yet been obtained at San Pedro.
270 CALIFORNIA ACADEMY OF SCIENCES.
The species of this genus are distributed in all seas. All our West American
forms have the columellar fold internal and hardly to be seen without breaking away
part of the whorls.
The number of species is so great, and they are so .similar to one another, that
a number of sections, based chiefly on the types of scidpture, have been found con-
venient in treating of them. Most of these sections grade into one another through
peripheral species.
Section atrioturhoiiillu Sacco.
Sttiol7irbo7iilla ShCCO, I. Moll, del Piedmonte e della Liguria, p. 94, 1892.
Shell as in Chemnitzia, but very finely and closely spirally striated on the spire and base.
Type, Strioturhonilla alpina Sacco, I. c.
284. Turbonilla (Strioturbonilla) muricata Carpenter.
Chemnitzia muricata Cpr., Mazatlan Cat., Brit. Assn. Rept., 1856, p. 260.
Shell small, slender, solid, rather thin, milk-white; nuclear whorls two and one-half, heli-
coid, smooth, one-third sunken, their axis being at right angles to the a.xis of the post-nuclear
whorls; post-nuclear whorls flattened, ornamented by eighteen to twenty-two very prominent,
elevated, convex-topped, slightly oblique axial ribs, which extend to the suture posteriorly, but fuse
just before reaching the suture anteriorly; ribs on body-whorl fuse abruptly at angle; the intercostal
spaces appear as deep channels about as wide as the ribs; the suture appears very distinct, owing to
a sharp angulation on the upper part of the whorl, and a slight contraction at the base; body-whorl
rather short, rounded, smooth on base, except for fine, incremental lines; aperture subquadrate, the
outer lip meeting the columella at almost right angles.
Dimensions. — Long. 5.4 mm.; lat. 1.3 mm.; altitude of body-whorl, 1.7 mm.
This species resembles T. stearnsii, but may be distinguished from that species
by more elevated, narrower and more numerous ribs and by the stronger angulation
above. The specimen examined lacked prominent spiral sculpture as far as the
writer was able to determine. This specimen was identified by Dr. Dall, but the
species was omitted from the text prepared by Dall and Bartsch.
Rather common in the up])er San Pedro series of San Pedro and LosCerritos;
rare in the lower San Pedro series at Deadman Island and San Pedi'O.
Living. — Gulf of California to Mazatlan (Carpenter).
Pleistocene. — San Pedro (Arnold).
285. Turbonilla (Strioturbonilla) similis C. B. Adains.
Chemnitzia similis C. B. Ads., Catalogue Panama Shells, No. 228, Ann. N. Y. Lye. Nat. Hist.,
Vol. V, 1852, p. 392.
Shell small, slender, solid, milk-white, thick; nuclear whorls two and one-half, smooth,
helicoid, about one-third sunken, their axis being at right angles to the axis of the post-
nuclear whorls; post-nuclear whorls nine, somewhat flattened, ornamented by fourteen to eighteen
prominent, broad, convex, oblique, axial ribs, which traverse nearly the whole of the exposed
ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 271
portion of the whorls, but fuse anteriorly before reaching suture; the ribs are bent slightly forward
near their posterior extremity; intercostal spaces deep, narrow; spiral sculpture fine but conspicu-
ous; the sutures are deeply impressed, with smooth sides, caused by the fusion of the ribs before
reaching the sutures; body-whorl rounded, smooth below, except for minute incremental lines and
spiral ornamentation. Aperture subquadrate; the outer lip joins the straight, somewhat revolute
columella at a right angle.
Dimensions.— Y^on^. 5 mm ; lat. i.i mm.; altitude of body-whorl 1.4 mm.
Tliis species somewhat resembles 2\ siearnsii, but is di.stinguisliable from that
species by the less number and greater prominence of the ribs, wliich in some cases
bend slightly forward near their posterior extremity. 2\ sbnilis was identified by
Dr. Dall; but the species was omitted from the text prepared by Dall and Bartsch.
Rare in the lower San Pedro series at Deadman Island and San Pedro;
common in the upper San Pedro series at San Pedro and Los Cerritos.
Living. — Gulf of California to Panama (Carpenter).
Pleistocene. — San Pedro (Arnold).
286. Turbonilla (Strioturbonilla) stearnsii D. £ B., sp. nov.
Plate II, Figs. 5 and 5a.
Shell milk-white, rather stout; nuclear whorls two, small, helicoid, their axis being at right
angles to the axis of the post-nuclear whorls; post-nuclear whorls very slightly convex, almost
flattened, somewhat contracted at the base, and strongly shouldered at the summit, traversed by
eighteen to twenty-six oblique, flexuose, axial ribs, which render the summits of the whorls wavy;
intercostal spaces deep, terminating a little above the periphery, thus leaving a narrow, plain band
above the suture, as in T. torqicata siylina; the entire surface of the whorls is marked by numerous
faint, wavy, spiral .striations, which also ornament the otherwise plain basal portion of the last whorl;
suture well defined, slightly channeled; aperture subovate, anterior angle obtuse; outer lip thin,
joining the short, somewhat revolute columella in a gentle curve.
Dimensions. — Long. 9.2 mm.; diam. 2.3 mm.
The type, which has eleven and one-half post-nuclear whorls, is from the post-
Pliocene of San Diego.
This species in a general waj'' resembles T. torquata stijlina, but differs from it
in being much more robust, of greater diameter throughout, and in having the fine,
wavy sculpture characteristic of the section.
Turhonilla f Strioturbonilla J siearnsii occurs quite abundantly in the post-
Pliocene deposits at San Diego and San Pedro. It also occurs recent in the Gulf of
California. The name is proposed in honor of Dr. R. E. C. Stearns of Los Angeles,
who collected many sj^ecimens of this group.
287. Turbonilla (Strioturbonilla) torquata Gould.
Platk II, Figs. 4 and 4a.
Chemnitzia torquata Gld., Bost. Jour. Nat. Hist., Vol. IV, 1853, p. 384, PI. XIV, fig. 16.
Shell slender, solid, milk-white, entire suriace marked by faint, wavy, spiral striations;
nuclear whorls three, helicoid, their axis being at right angles to and to one side of the post-nuclear
272 CALIFORNIA ACADEMY OF SCIENCES.
whorls; post-nuclear whorls somewhat flattened, ornamented by sixteen to twenty-two broad,
oblique, somewhat flexuose axial ribs, which traverse five-sixths of the exposed portion of the whorls,
then fuse, leaving a band above the suture and the base of the last whorl devoid of sculpture; the
intercostal spaces appear as grooves gouged out of the shell, their bases marking the fusing point of
the ribs; they are equal to the ribs in breadth; the sutures are well defined, owing to the very slight
shouldering of the summit and the slight contraction of the base of the whorls; last whorl slightly
angular at the periphery; aperture subovate; the rather thick outer lip joins the straight, somewhat
revolute columella at almost a right angle.
Dimensions. — Long. 10.6 mm.; diam. 2.5 mm.
The specimen figured is from the post-Pliocene of San Diego.
This species occurs living along the California coast at 2^'"esent, but appears
far more abundant in the fossil state. More than five hundred individuals referable
to this form have been examined, only six of which were recent, the remainder
being post-Pliocene fossils from the vicinity of San Pedro and San Diego.
288. Turbonilla (Strioturbonilla) torquata, var. stylina Carpenter.
Plate I, Fio.s. 10 and lOn.
Chemnitzia (f torquata var. j stylma Cpr., Ann. Mag. Nat. Hist., 3rd Sen, Vol. XV, 1865, p. 396.
Shell like T. torquata, but more slender, with but two nuclear whorls; having more axial
ribs, twenty-two to twenty-eight on the post-nuclear whorls, and the intercostal spaces extending
further down upon the whorls, thus diminishing the breadth of the plain band above the sutures;
entire surface marked by faint, wavy, spiral striations.
Dime?isions. — Long. 8 mm.; diam. i.g mm.
The specimen figured is from Monterey. This variety has been found as far
north as Port Etclees, Alaska. It occurs abundantly as a post-Pliocene fossil in the
vicinity of San Pedro and San Diego.
Section Lancea Peas(\
Lancea Pease, Am. Journ. Conch., Vol. IH, 1867, p. 293. Type, Turbonilla {Laiicea) elo7igata
Pease, ^=Pyrgostyhcs Monterosato, Conch. Medit., p. 90, 1884.
Turbonillas with strong axial ribs and spiral sculpture, provided with thickened varices at
irregular intervals on the spire, which are usually accompanied by internal lirations of the outer lip.
289. Turbonilla (Lancea) aurantia (kirpcnier.
Chemnitzia tridentata (? v&r.) aurantia Cpii., Brit Assn. Rept., 1863, p. 659; Jour, de Conch., Vol. XII,
1865, p. 147.
Shell small, slender, solid, rather thick, reddish-brown; first tliree post-nuclear whorls convex,
five remaining post nuclear whorls (nearly) flat; whorls ornamented by twenty to twenty-six broad,
evenly rounded, only very slightly oblique axial ribs, which extend nearly Irom suture to suture;
the intercostal spaces appear as narrow grooves, their width is much less than the width of the ribs;
the spiral striations on the base and between the ribs are very faint; the sutures are well defined and
deep, owing to a distinct shouldering of the whorls above, and an equal contraction of the whorl at
ARNOLD — THE PALEONTOLOGY AND STKATIGKAPHY OP SAN PEDRO. 273
the base; last whorl slightly angular at the periphery, base of this whorl smooth except for very fine
axial, incremental lines, and nearly obsolete spiral striations; aperture subquadrate, the thick outer
lip joins the nearly straight, somewhat revolute columella at almost a right angle.
Dimensions. — Long. 6 mm.; lat. 1.8 mm.; body-whorl, altitude 2 mm.
This species somewhat resembles T. tridentata in general appearance, but may
be di.stinguished from that species by the greater number of ribs, which are closer
together and broader, the narrower interspaces and fewer whorls. The si^ecimen
described lacks the nuclear whorls, which were broken off; the spiral sculpture on
this specimen is also very faint, and would have been overlooked if a very high-
power magnifier had not been used. This specimen was identified by Dr. Dall; but
the species was omitted from the text prepared by Dall and Bartsch.
Rare in the lower San Pedro series at Deadman Island and San Pedro; and
in the upper San Pedro series at Los Cerritos and San Pedro.
Living. — Puget Sound to Santa Barbara (Carpenter) : San Pedro (Williamson).
Pleistocene. — San Pedro (Arnold).
290. Turbonilla (Lancea) tridentata Carpenter.
Pi^TE II, Figs. 1 and la.
Chemnitzia tride7itala Cpr., Jour, de Conch., Vol. XIII (3rd Ser., Vol. V), 1S65, p. 147.
Shell large, broad; chestnut colored, obscurely banded; nuclear whorls three, helicoid,
about one-third immersed, scarcely extending beyond the margin of the spire, their axis being at a
right angle to the axis of the later whorls; post-nuclear whorls slightly convex, somewhat contracted
below and slightly shouldered at the summit; traversed by about twenty to twenty-four strong, well-
rounded, somewhat oblique axial ribs, which continue faintly over the decidedly angular periphery
of the last whorl and the base to the umbilical region; these ribs are considerably enfeebled on the
last whorl of old shells and frequently become almost obsolete on these; the exposed portion of the
whorls is traversed by six to ten spiral grooves, which appear most prominently in the shallow and
broad intercostal spaces, and less so on the ribs; these deep spiral lines are regularly spaced, leaving
a broader interval on the middle of the exposed portion of the whorl; the base of the last whorl is
likewise ornamented by spiral grooves, but here they appear less developed than on the spire; in
addition to this the entire surface of the shell is marked by numerous very fine, somewhat wavy,
spiral and axial striae, which show most prominently on the last whorl and base, and give the shell a
very minutely reticulated secondary sculpture; at irregular intervals the whorls are marked by thick
callous varices, which are usually of a lighter color than the remainder of the shell; aperture large,
subquadrate; posterior angle acute; outer lip thin, having three strong internal lirations, joining the
whitish, short, straight, revolute columella at a little less than a right angle; by transmitted light
two spiral, light color-bands become apparent on the inside of the lip, each of which is bordered by
a zone of a darker color than the remaining shell; the general color effect of the exterior is that of a
flesh-colored shell, covered by a dark epidermis, which is stretched tight over the ribs, permitting
the lighter color beneath to shine through it at their summits.
Dimensions. — Long. 11. i mm.; diam. 3.2mm. (Dr. Carpenter's type, collected at Monterey,
and having 11 post-nuclear whorls). Long. 12.8 mm.; diam. 3.6 mm. (Specimen figured, which is
from San Pedro).
Fossil specimens from the post-Pliocene of California are larger, have fewer
ribs, and more of the deep revolving lines than recent ones.
(35) March 30, 1903.
274 CALIFORNIA ACADEMY OF SCIENCES.
291. Turbonilla (Lancea) pentalopha D. 1- B., sn. nov.
Plate I, Figs. 1 and 1 a.
Shell chocolate-brown, inflated, stubby; nuclear whorls three, helicoid, moderately large,
about one-third immersed, their axis being at a right angle to the axis of the later whorls; post-nuclear
whorls at first a little rounded, later flattened, scarcely contracted at base, shouldered at the summit,
adorned by twenty to twenty-eight strong, rounded, slightly oblique and somewhat flexuose axial
ribs, which pass over the periphery of the last whorl and gradually disappear on the base; intercostal
spaces rather deep, marked by five or six narrow, deep, subequally spaced spiral grooves, which
encroach upon the ribs and in places extend over them; base of the last whorl very short, abruptly
rounded, depressed at the umbilical region, marked by seven equally-spaced spiral striae of the
same nature as those of the exposed portion of the preceding whorls, the first one above and the first
one below the periphery are a little farther apart than the rest and map out the path for the shoulder
of the succeeding whorl; aperture large, ovate; outer lip thin, meeting the short, somewhat twisted
and revolute columella in a broad curve; the reflexing of the thin columella and the sudden curving
of the base cause the shell to appear subumbilicate.
By transmitted light the ribs become apparent on the inside of the outer lip, and the spiral
striae appear as so many faint red bands; at irregular intervals five strong spiral lirae are developed
on the inside of the outer lip, the upper four being equally spaced, the fifth or anterior one being a
little closer to its neighbor; no varices appear to accompany the internal lirations, a character in
which it differs from typical Lancea.
Dimensions. — Long. 8.5 mm.; diam. 2.3 mm.
The type, which is figured, was collected at San Diego, and has ten post-
nuclear whorls.
Recent specimens a2ipear to range from San Pedro to Lower California. Fos-
sils of this species have been found at Deadman Island.
Section Pyrgiscus Philippi.
Pyrgiscus Phil., Weig. Arch., Bd. VII, 1841, p. 50. Type, Melania rufa Phil., 1. c. =Pyrgostelis
MoNTEROSATO, Conch. Medit., p. 89, 1884.
Turbonillas having prominent axial ribs and spiral sculpture, but no varices or internal lira-
tions; columella usually somewhat flexuous.
[S. D.] Turbonilla (Pyrgiscus) auricoma D. & B., sp. nov.
Plate I, Figs. 4 and ia.
Shell slender, attenuated, brown, lighter on the early whorls, becoming quite dark on the
last; nuclear whorls two and one-half, large, helicoid, not immersed, projecting somewhat beyond
the outline of the spire, their axis being at a right angle to the axis of the later whorls; post-nuclear
whorls at first somewhat rounded, later flattened, traversed by eighteen to twenty-four strong,
moderately wide axial ribs, inclined slightly toward the aperture; these continue quite prominently
over the well-rounded periphery and base of the last whorl to the umbilical region; intercostal spaces
somewhat irregular in width, deep, ornamented by about eight moderately deep, wavy, spiral strire,
which are red in color; whorls slightly contracted at base and shouldered at the summit, which is
rendered wavy by the ribs; suture quite prominent; the base of the last whorl is well rounded,
inflated, and ornamented by nine subequally spaced spiral striae of a similar character to those of the
ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 275
exposed portions of the whorl; aperture large, ovate, somewhat produced at the base; posterior
angle acute; outer lip thin, joining the oblique, strongly revolute columella in a wide curve; the
strongly reflexed columella and the decided rounding of the last whorl give the shell a subumbili-
cated appearance; the peritreme is rendered almost complete by the strong callus which extends
from the posterior angle of the aperture to the insertion of the columella; by transmitted light the
interior of the outer lip appears beautifully marked by narrow, wavy, sometimes branching, spiral
threads of red, laid on a ground of pale yellow, the middle one of which is the broadest, and marks
the periphery.
Dimensio7is. — -Long. 7.2 mm.; diam. 1.9 mm.
The type is from Scammou's Lagoon, Lower California, and has twelve post-
nuclear whorls.
This species also occurs recent along the California coast, and has been found
as a post-Pliocene fossil at San Diego.
292. Turbonilla (Pyrgiscus) latifundia D. & B., sp. nov.
Plate III, Figs. 5 and 5a.
Shell very broadly conic, milk-white; nuclear whorls two and one-half, with moderately
elevated spire, extending a little beyond the outline of the first post-nuclear whorl on one side, about
one-third immersed, their axis being at a right angle to the axis of the later whorls; post -nuclear
whorls well rounded, each much broader at its base than the summit, ornamented by about fourteen
strong, rounded, oblique, axial ribs and seven or eight deeply impressed, very prominent spiral
lirations, extending across the intercostal spaces, which are about twice as wide as the ribs, and upon
the sides of these, but they do not cross their summits; both ribs and intercostal spaces pass very
feebly over the decidedly angulated periphery (this angulation is much more pronounced in young
specimens than in the adultj; the short base is marked by about seven continuous, somewhat wavy,
subequally spaced, spiral lines, much weaker than the spiral sculpture on the exposed portion of the
whorls; aperture subquadrate, posterior angle acute; outer lip thin, showing the external sculpture
within by transmitted light; columella straight and revolute.
Dbnensions. — Long. 5.8 mm.; long. spir. 5.2 mm.; diam. 2 mm.
The type is a post-Pliocene fossil from San Pedro, and has nine post-
nuclear whorls.
This species occurs also in the post-Pliocene deposits of Deadman Island.
So far no recent representatives have been found.
293. Turbonilla (Pyrgiscus) tenuicula Gould.
Plate II, FiG.s. 7 and 7a.
Chemnitzia tenuicula Gld., Bost. Jour. Nat. Hist., Vol. VI, 1853, pp. 383, 384, PI. XIV, fig. 15.
Shell small, elongated, lanceolate, turreted, rather solid, shining, wax yellow, a little dusky
below the suture; whorls ten, flat, slightly shouldered above, marked by about twenty direct, longi-
tudinal folds, the summits of which are cut by numerous fine revolving striae, deeper in the interstices,
which also extend over the base of the shell, though the folds terminate at the periphery, or are
extended in delicate furrows; aperture narrow, ovate; lip sharp; revolving striae apparent within.
Dimejisions. — Length 7.5 mm.; diam. 1.3 mm.
Found at Santa Barbara.
276 CALIFORNIA ACADEMY OF SCIENCES.
The above is the original description by Gould. Tnrbonilla fPyrgiscusJ
tenuiculn Gould is the most abundant and most variable species of all the west
American forms, presenting many varieties or incipient species; to describe these
would not aid science or the collector, but would only add to the confusion which
this paper is intended to dispel. The following comprehensive description will
embrace, we believe, all the forms coming under this name: —
Shell slender to somewhat stubby and inflated, varying in color from milk-white to waxy
yellow or to dark brown, variously banded or plain monocolored; nuclear whorls three, moderately
large, planorboid, slightly slantingly immersed; post-nuclear whorls rounded to flattened, contracted
at base and strongly shouldered at the summit, traversed by eighteen to twenty-eight strong axial
ribs, which are excurved and usually somewhat thickened, and connected at their summits, which
appear beaded; these ribs extend feebly over the rounded base of the last whorl; the entire shell is
crossed by spiral lines, ten to sixteen or more of which appear on the exposed portion of the whorls,
and more, closer placed, wavy ones on the base of the last whorl; the suture is deep, subchanneled
and wavy; aperture ovate, produced at base; outer lip thin, meeting the oblique, slightly curved and
revolute columella in a broad curve; a faint callus connects the posterior angle of the ap^erture with
the insertion of the columella.
Dimensions. — Long. 6.5 mm.; diam. 1.9 mm.
The specimen figured is from the Todos Santos Bay, Lower California, and
has nine post-nuclear whorls. One of the same number of whorls from San Pedro
measures: long. 6.2 mm; diam. 1.7 mm.
Recent specimens in our collection range from Monterey to Todos Santos
Bay, Lower California. The species occurs also in the post-Pliocene beds at San
Diesro and San Pedro.
--t)^
294. Turbonilla (Pyrgiscus) crebrifilata Carpenter.
Plate II, Figs. 6 and 6(x.
Chemnitzia crebrifilata CpR., Ann. Mag. Nat. Hist., 3d Ser., Vol. XV, 1865, p. 395.
Shell milk white to waxy yellow to yellowish brown in color, and of similar shape to
T. tenuiaila Gld. ; nuclear whorls three, helicoid, slantingly one-third immersed; extending a little
beyond the outline of the spire on one side; post-nuclear whorls at first well rounded, later flattened,
strongly shouldered at the summit and ornamented by eighteen to twenty-four very pronounced, acute
and somewhat flexuous, irregularly slanting axial ribs, which are outcurved at the summit of the
whorl and there held in union by a spiral thickening of the wavy shoulder; intercostal spaces moder-
ately deep and very broad, at least double the width of the ribs, with a quite deep depression immedi-
ately below the shoulder, which causes the summits of the whorls to appear crenulate, and
ornamented by about eight to ten spiral striations of varied width and spacing; these striations
frequently extend over the ribs and cause the intermediate ground to appear as raised ridges; suture
deep and wavy; periphery and base of the last whorl well rounded, the axial ribs extending faintly
over the base to the umbilical region; the base is marked by spiral striations similar to those of the
exposed portion of the whorls, but here they are more wavy and adjacent; aperture ovate, rather
large, acute posterior angle, and the base somewhat produced; outer lip thin, meeting the oblique,
somewhat twisted and revolute columella in a gentle curve; a faint callus extends from the posterior
angle of the aperture to the pillar. By transmitted light a broad, white, revolving band becomes
apparent in the peripheral region of the aperture in dark-colored specimens.
Dime7isions. — Long. 5.4 mm.; diam. 1.6 mm.
ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 277
The specimen figured has nine post-nuclear whorls. Fossil specimens from
the post-Pliocene of California attained a much larger size than recent representa-
tives of the species. A fragment of a specimen collected at San Diego, consisting
of the last four whorls, has a diameter of 2.2 mm.
295. Turbonilla (Pyrgiscus) subcuspidata Carpenter.
Plate II, Figs. 2 and 2a.
Chemnilzia siibcuspidala CvR., Proc. Cal. Acad. Sci., Vol. Ill, 1S65, p. 220, No. 670.
Shell stout, strong, somewhat inflated, whitish to waxy yellowish; nuclear whorls three,
helicoid, of moderate size, slantingly one-fourth immersed, slightly extending beyond the general
outline of the spire on one side; post-nuclear whorls well rounded, the last two somewhat flattened,
contracted at base, outcurved and muricated at their summits, traversed by sixteen to twenty very
strong, flexuose, more or less irregular axial ribs, which extend strongly upward and render the
shoulder subcuspidate and very wavy; these ribs become enfeebled on the last whorl and almost
obsolete on the base, extending only very feebly over the well rounded periphery to the umbilical
region; intercostal spaces wider than the ribs, undulating, traversed by five to twelve deep spiral
striations, which extend less prominently over the ribs and cause the whorls to appear as if they were
wound by a series of overlapping bands of varied width; these bands vary in number and con-
sequently in width, being fewer and most prominent on the earlier whorls, as are the ribs, later on
becoming enfeebled; a very slight groove passes about the periphery of the last whorl and maps out
the route for the suture; the spiral sculpture of the entire last whorl is very regular, there being about
thirteen subequally spaced strioe above the periphery and eighteen on the base; the sutures are very
deep, subchanneled; aperture ovate; posterior angle acute; outer lip moderately thick, rather effuse
at base, joining the oblique, somewhat reflexed columella in a gentle curve; a faint callus connects
the posterior angle of the aperture with the insertion of the columella; by transmitted light a faint
light, revolving band becomes apparent in the peripheral region within the aperture.
Dimensions. — Long. 6 mm.; diam. 2 mm.
The specimen figured and described is Dr. Carpenter's type; it has eight and
one-half post-nuclear whorls, and comes from San Diego. Fossil specimens from the
same locality are even more robu.st. One of seven post-nuclear whorls measures:
long. 5.6 ram.; diam. 2.1 mm. Found in the post-Pliocene deposits of San Pedro.
Section Pyrgisculus Monterosato.
Pyrgismlus Monterosato, Conch. Medit. , p. 88, 1884. Type, Melayiia scalaris Philippi.
Turbonillas with strong axial ribs and lamellate spiral sculpture, having a decidedly sloping
shoulder at the summit.
296. Turbonilla (Pyrgisculus) laminata Carpenter.
Plate II, Figs. 8 and 8a.
Dunkeria laminata Cpr., Ann. Mag. Nat. Hist., 3rd Ser., Vol. XV, 1865, p. 396.
Shell white to dark brown, plain or variously banded; nuclear whorls three, large, tumid,
helicoid, slantingly slightly immersed; post-nuclear whorls well rounded, ornamented by twenty-two
to twenty-eight strong axial folds, which pass feebly over the well-rounded periphery and base of the
278 CALIFORNIA ACADEMY OF SCIENCES.
last whorl to the umbilical region, and five very strong, broad, flat, subequally spaced spiral ridges,
which give the spire a reticulated, pitted pattern; the portions between the ribs and the spiral folds
appear as small, deep pits of a more or less circular outline, while the ribs appear thickened where
they are crossed by the spiral bands; a sixth spiral band maps out the path for the shoulder of the
succeeding whorl on the periphery of the basal whorl, while the base proper is marked by about
eight spiral striations, which are strongest at the periphery and gradually weaken toward the
umbilicus; the whorls are marked by a quite prominent sloping shoulder, which extends from the
first revolving band to the summit; the suture is deep, subchanneled; aperture broadly ovate, some-
what effuse, with the posterior angle acute; outer lip thin, crenulate by the spiral ridges, meeting the
curved and revolute columella in a broad curve; a thin callus extends from the posterior angle of the
aperture to the umbilical region.
Dimensions. — Long. 6.8 mm.; diam. 2.2 mm.
The specimen figured is from San Pedro, and has nine whorls.
Post-Pliocene specimens from California are usnally larger, though quite
identical in every other respect. One of nine post-nuclear whorls measures: long.
8.6 mm.; diam. 2.4 mm. The smallest forms come from Lower California. One of
eight post-nuclear whorls measures: long. 4.9 mm.; diam. 1.6 mm.
Section Pyrgolampros Sacco.
Pyrgolampros Sacco, I Moll, del Piedmonte e della Liguria, p. 85, 1892. Type, P. mioperplicatulus
Sacco.
Turbonillas with more or less weak axial ribs, which always almost disappear as they pass
over the periphery and base of the last whorl, and many very fine, faint spiral striations; columella
usually somewhat flexuous.
297. Turbonilla (Pyrgolampros) lowei D. I- B., sp. nov.
Plate I, Fias. 5 and 5a.
Shell of medium size, light golden brown; nuclear whorls three, small, helicoid, partly
slantingly immersed; post-nuclear whorls very similar to those of T. vancouverensis Baird, in out-
line, moderately convex, strongly contracted at base and moderately so at the summit, bounded by a
prominent suture. The early whorls increase less rapidly in diameter than the later ones, and are
ornamented by more and weaker axial ribs than the later ones; these ribs slant toward the aperture;
beginning with the sixth whorl the shell assumes a more robust character, the whorls become broader
and are ornamented by twenty to twenty-two strong, somewhat flexuose, almost vertical axial ribs,
which extend faintly over the angular periphery of the last whorl to the umbilical region; the entire
shell is traversed by many very fine, very closely placed spiral stri:e; aperture subrhomboid, outer lip
thin, produced and flaring at its junction with the twisted and revoluted columella.
Dimensiotis. — Long. 7.2 mm.; diam. 2.2 mm.
The type is from San Pedro, and has ten and one-half whorls. Sjiecimens
from the post-Pliocene of California are larger and more robust. One of ten normal
whorls measures: long. 8.1 mm.; diam. 2.4 mm. Fossil specimens occur abundantly
at San Pedro and San Diego.
This species is named in honor of Mr. H. N. Lowe, of Long Beach, Califor-
nia, to whom we are indebted for material bearing on our study of these difficult
little shells.
AENOLD — THE PALEONTOLOGY AND STKATIGRAPHY OF SAN PEDRO. 279
[S. D.] Turbonilla (Pyrgolampros) lowei, var. pedroana D. & B., var. nov.
Plate II, Figs. 3 and 3a.
Shell similar to T. iozvei, both in general form and sculpture, but more robust, broader and
less attenuate; nuclear whorls three, half immersed; post-nuclear whorls with ribs of more uniform
size, not crowded and enfeebled on the early whorls as in T. Iozvei; basal portion of the whorls of a
darker color than the upper, causing the exposed portion of the whorls to appear banded above the
suture; whorls faintly shouldered, otherwise as in T. lowei.
Dimeyisions. — Long. 7 mm.; diam. 2.3 mm.
The type has nine post-nuclear whorls. Specimens from Victoria, B. C, are
still broader. One of seven post-nuclear whorls measures: long. 5.5 mm.; diara.
2.1 mm. The northern specimens are also somewhat lighter in color. This variety
is found living from Victoria, B. C, to San Diego, and occurs fossil in the post-
Pliocene beds at San Diego.
298. Turbonilla (Pyrgolampros) arnoldi D. it B., sp. nov.
Plate I, Fig. 7.
Shell whitish, robust, more or less inflated; nuclear whorls decollated; post-nuclear whorls
flattened, somewhat contracted at base, and slightly outcurved at the summit, traversed by about
twenty-two to twenty-eight more or less irregular axial ribs, slanting slightly toward the aperture,
and which extend less prominently over the well-rounded periphery of the last whorl to the umbilical
region; suture deep, subchanneled, somewhat undulate; the entire surface of the whorls is covered
with fine, very closely placed, wavy, spiral striations; last whorl somewhat produced; aperture large,
subovate, with a thin outer lip, which is decidedly effuse at base, and meets the somewhat oblique and
revolute columella in a broad curve.
Dimensions. — Long. 7.6 mm.; diam. 2.3 mm.
The specimen figured has eight post-nuclear whorls.
This species so far has only been reported from the post-Pliocene deposits
of Deadman Island. It is named in honor of Mr. Ralph Arnold, of Pasadena,
California.
299. Turbonilla (Pyrgolampros) gibbosa Carpenter.
Plate I, Figs. 2 and 2a.
Chemnitzia gibbosa Cpr., Cat. Maz. Shells, p. 430, No. 525, 1857.
Shell inflated, robust, broad and stumpy, of light, fulvous coloration; nuclear whorls deeply
immersed, very slightly exposed at the tip, their axis apparently being at a right angle to the axis of
the later whorls; post-nuclear whorls flattened, somewhat contracted at the periphery and rounded
at the summit, traversed by about sixteen to twenty-four broad, coarse, irregularly slanting axial
ribs, which extend over the inflated periphery of the last whorl to the umbilical region, appearing less
prominent on the base; the entire surface of the shell is covered by very minute, close, spiral
striation; suture subchanneled and wavy; aperture ovate, outer lip thin, joining the twisted and
revolute columella in a broad curve.
Di?nensions. — Long. 5.6 mm.; diam. 2.1 mm.
The specimen figured has seven post-nuclear whorls.
280 CALIFORNIA ACADEMY OF SCIENCES.
This is certainly the most unattractive member of the genus. Dr. Carpenter
described it as a recent form in his Catalogue of Mazatlan Shells. We have a single
recent specimen from Monterey. It appears to be more abundant in the post-
Pliocene dejiosits of Deadman Island.
300. Turbonilla (Pyrgolampros) adleri D. £ B., sp. nov.
Plate I, Fig. 9.
Whorls decidedly flattened, contracted at the periphery and shouldered at the summit;
a.\ial ribs only faintly indicated near the summit of the whorls by distant, shallow, impressed lines,
which mark their lateral margins; the entire shell is traversed by faint, closely placed, wavy, spiral
striations; suture quite deep, subchanneled; periphery of the last whorl rounded; aperture sub-
rhomboidal, posterior angle obtuse; columella reflexed, strongly twisted, giving it the appearance of
being provided with a broad, rounded fold; a faint callus connects the columella with the posterior
angle of the aperture.
Dimensions. — Long. 9.3 mm.; diam. 3.2 mm.
Only two fragments of this specimen have so far come to our notice; both are
from the post-Pliocene deposits of Deadman Island.
The type consists of the last six post-nuclear whorls. It may, however, have
had eleven whorls normally.
Genus Pyramidella Lamarck.
Shell turriculated, spire elevated, a-xially ribbed; columella with three anterior plications;
outer lip sharp, sometimes plicate within.
Pyramidella plicata Lamarck is a characteristic species.
301-. Pyramidella conica Adams, var. variegata Carpenter.
Obeliscus variegata Cpr., Brit. Assn. Rept. , 1863, p. 65S; Ann. Mag. Nat. Hist., 3rd Ser., Vol. XIV,
1864, p. 46. Keep, West Coast Shells, p. 54, fig. 35, 1892.
Pyramidella conica Ads., var. variegata Cpr., Williamson, Proc. U. S. Nat. Mus., Vol. XV,
1892, p. 208.
Shell small, elongate-conical; spire elevated; apex acute; whorls ten, flat, smooth; suture
distinct; aperture subovate; outer lip thin; columella truncated, with three plications.
Dimensions. — Long. 13 mm.; lat. 3.6 mm.; defl. 20 degrees.
Rare in upper San Pedro series of San Pedro; one specimen. This species
was omitted from the text prepared by Dall and Bartsch. In examining some
Turhonillas in the collection of Mr. Henry Hemphill the writer found one of this
sjiecies labeled "Turbonilla mexicana Dall and Bartsch." This name is the one
under which it probably should appear, but not having an opportunity to consult
Dr. Dall on the subject, this note is appended.
Living. — San Diego; Lower California (Carpenter).
Pleistocene. — San Pedro (Arnold).
AKNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDKO. 281
Genus Odostomia Fleming.
Odostomia Fleming, Edinburgh Encyclopedia, Vol. VII, Pt. I, p. 76, 1817 } {ex parte).
Type, Odostomia plicata MoNT.
Shell with sinistral nucleus, subglobose to broadly conic; spire rarely elevated as in Tiir-
bonilla; sculpture varying in the different sections from plain (^Odostomia, s. s.) to highly ornamented
[Chrysallida); columella provided with a single fold, which is rarely obsolete.
Animal as in Turbonilla. The species of this genus are distributed in all seas.
The original description of this genus included chiefly small land shells, with dentate
a})ertures, but also a few marine species. The land shells had already received
names, so the marine species were left to carry Fleming's name, a fact recognized
by him in later publications. The rarity of the original edition of the Edinburgh
Encyclopedia has made it very difficult to ascertain the facts in regard to this genus,
and the true date of its publication, but we believe the facts to be now established as
above stated. The species cited in the original publication are 0. inter stincta,
0. unidentata, 0. plicata, 0. sandvicensin and 0. insoulpta.
Section Odostomia Fleming, s. s.
Odostomia Fleming, Edinburgh Encyclopjedia, Vol. VII, Pt. I, p. 76, i8iy (ex parte).
Type, Odostomia plicata MoNT.
Odostoniias of more or less conical outline, devoid of all sculpture, except incremental lines,
and having a more or less prominent columellar fold.
302. Odostomia tenuis Carpenter.
Platk I, Fig. 14.
Odostomia tenuis Cpr., Cat. Maz. Shells, p. 412, 1856.
Shell slender, conic, umbilicated, dingy white; nuclear whorls small, immersed; post-nuclear
whorls very slightly convex, almost flattened, scarcely contracted at base, and hardly shouldered;
suture not very prominent, hardly channeled; base and periphery of the last whorl well rounded;
aperture quite large, ovoid, posterior angle acute, outer lip somewhat contracted at its middle; colu-
mella very flexuous, slender and revolute; parietal wall covered by a faint callus; columellar fold
strong opposite the umbilical chink.
Dimensio7is. — Long. 5.7 mm.; diam. 2.6 mm.
The specimen figured is from Santa Rosa Island, California, and has seven
post-nuclear whorls.
The species appears to range in the recent state from Washington to Cali-
fornia, and has been found in the post-Pliocene depo.sits of San Diego, San Pedro,
and Ventura.
Section Evalea A. Adams.
Evalea A. Adams, Ann. Mag. Nat. Hist., 3d Sen, Vol. VI, i860, p. 22. Type, Odostomia (Evalea)
elegans A. Adams.
Ondina De Folin, Fonds de la Mer, p. 214, 1870. Type, Ondina sulcata De Folin, 1. c.
Odostomias without axial sculpture, having spiral striation or liration.
( 36 ) March 31, 1903.
282 CALIFORNIA ACADEMY OF SCIENCES.
[S. D.] Odostomia (Evalea) stearnsii D. <("■ B., sp. nov.
Plate I, Fiu. 12.
Shell regularly elongate-conic, turreted, subumbilicated, milk white; nuclear whorls small,
slantingly immersed; post-nuclear whorls rounded, somewhat contracted at base and strongly shoul-
dered at the summit; suture profound, channeled; last whorl rather inflated; aperture large, pyriform,
posterior angle obtuse, outer lip slightly contracted at the middle; columella decidedly oblique, flex-
uous and reflexed, the narrow parietal wall being covered by a faint callus; a weak columellar fold
appears opposite the umbilical chink; the entire shell is ornamented with very fine spiral striation.
Dimensions. — Long. 5.2 mm.; diam. 2.2 mm.
The type has eight post-nuclear whorls, and is from the post-Pliocene of San
Diego, which is the only locality, so far, from which this species has been reported.
303. Odostomia (Evalea) gouldii Carpenter.
Plate I, Fig. 15.
Odostomia (? war.) gouldii Cpr., Ann. Mag. Nat. Hist., 3rd Ser., Vol. XV, 1865, p. 30.
Shell solid, inflated, shining, subdiaphanous to milk-white; nuclear whorls obliquely im-
mersed; post-nuclear whorls rounded, not contracted at base, and but very feebly shouldered at the
summits; base and periphery of the last whorl well rounded; aperture large, ovoid, posterior angle
acute; outer lip well rounded, its anterior margin somewhat effuse at the junction with the twisted,
reflexed and appressed columella; columellar fold very prominent a little anterior to the upper end
of the columella; the entire shell is very feebly and closely spirally striated.
Dim.ensions. — Long. 5 mm.; diam. 2.8 mm.
The specimen figured has six post-nuclear whorls, and comes from Monterey.
The species ranges recent from Alaska to San Diego, Cal., occurring as a post-
Pliocene fossil in the last-named place, and also at San Pedro and Ventura.
Section Amaiira Moller.
Amaiira Moller, Index Moll. Groenl., p. 7, 1842. Type, A. Candida Moller, 1. c.
Odostomias of extremely large size, inflated, very heavy, usually devoid of all sculpture,
sometimes very minutely spirally striated.
This genus was supposed to be naticoid, but an examination of the authentic
specimens shows its relations to be with the Pyramidellidse. The account of the
animal in Fischer's Manual ap^Dears to have been taken from a true naticoid, perhaps
Amauro'p?,i?,, which Fischer wrongly includes as a section under Amnura; but this
account does not agree with Mijller's original diagnosis, nor with tlie characters of
Amaura, as determined from specimens collected in Greenland by Moller, which
show, when the back of the shell is ground away, the plait invisible from in front of
the aperture.
ARNOLD — THE PALEONTOLOGY AND STKATIGEAPHY OF SAN PEDBO. 283
[S. D.] Odostomia (Amaura) pupiformis Carpenter.
Plate I, Fig. 13.
Odostomia satura \zx. pupiformis Cpr., Ann. Mag. Nat. Hist., 3rd Ser., Vol. XV, 1865, p. 30.
Shell broadly conic, umbilicated, rather thin, white, shining, of rather rough exterior;
nuclear whorls immersed; post-nuclear whorls somewhat rounded and shouldered at the summit;
suture deep and channeled; base and periphery of the last whorl decidedly rounded; aperture large,
broadly ovate; posterior angle acute; outer lip somewhat effuse in its anterior margin; columella
thin and flexuose, provided with a prominent oblique fold a little anterior to the umbilicus; a weak
callus covers the parietal wall.
Dimensions. — Long. 6.4 mm.; diam. 3.3 mm.
The type was collected at Neeah Bay, Washington, and has six post-nuclear
whorls. The strong umbilication and the light weight of the shell enable one to
distinguish it quite readily from all the other forms of this section. The species
ranges recent from Alaska to San Diego. Fossil specimens have been found in the
post-Pliocene beds of San Diego.
304. Odostomia (Amaura) nuciformis, var. avellana Carpenter.
Plate I, Fig. 11.
Odostomia ( ? var.) avellana Cpr., Ann. Mag. Nat. Hist., 3rd Ser., Vol. XV, 1865, p. 30.
Shell large, stout and inflated, white; nuclear whorls small, immersed; post-nuclear whorls
somewhat rounded, rather broad, marked only by thin lines of growth; sutures quite prominent, sub-
channeled; base and periphery of the last whorl well rounded; aperture large, subovate; posterior
angle obtuse; outer lip somewhat contracted, while the anterior margin is somewhat efTuse; columella
short and flexuose, provided with a strong, broad fold just anterior to the umbilical chink; a strong
callus extends from the posterior angle of the aperture to the base of the columella and renders the
peritreme almost continuous.
Dimensiojis. — Long. 9.1 mm.; diam. 4.4 mm.
This is one of the large West Coast Odostomias, and ranges in the recent state
from Alaska to San Pedro. The specimen figured is from Neeah Bay, Washington,
the type locality. It has six post-nuclear whorls.
Fossil forms occur in the post-Pliocene deposits of Deadman Island, and also
at Ventura.
0. avellana differs from true 0. nuciformis in having the spire much more
elongated; it is therefore less pudgy than that form.
Section Chrysallida Carpenter.
Chrysallida Cpr., Cat. Maz. Shells, p. 416, 1857. Type, Chrysallida communis C. B. Adams.
Odostomias having strong axial ribs, crossed by equally strong spiral sculpture, which renders
the spire nodulose; the axial ribs pass only faintly over the base, while the spiral sculpture remains
quite prominent.
284 CALIFORNIA ACADEMY OF SCIENCES.
[S. D.] Odostomia (Chrysallida) diegensis D. <f- B., sp. nov.
P;,ATK I, Fig. S.
Shell elongate-conic, dingy white; nuclear whorls decollated; post-nuclear whorls flattened,
contracted at base and strongly shouldered at the summit; suture undulate, profoundly channeled;
about seventeen very strong, rounded, axial ribs cross the third and fourth, and twenty-two the
penultimate whorl; these ribs pass faintly over the well-rounded periphery of the last whorl to the
umbilical region; the first five whorls are encircled by four strong, spiral ridges, while the penultimate
shows an additional one; these ridges are not quite as broad as the axial ribs, but extend prominently
over them and the intercostal spaces; base ornamented by about ten spiral ridges of weaker char-
acter than those of the spire, and by the faint extensions of the axial ribs; aperture suboval, decidedly
produced and flaring at the junction of the outer lip with the columella (outer lip fractured in all
our specimens); columella somewhat twisted and reflexed, a bit being broken away at the umbilical
region in the type, disclosing a small umbilical chink which is opposite to the strong columellar fold;
a heavy callus connects the posterior angle of the aperture with the columella.
Dimensions. — Long. 4 mm.; diam. 1.6 mm.
The seven specimens of thi.s species in our collection all come from the post-
Pliocene deposits at San Diego. The type has seven post-nuclear whorls.
Section Oscilla A. Adams.
Oscilla A. Adams, Proc. Zool. Soc, 1867, p. 310. Type, Odostomia (^Evalea) lirata A. Ad.
Odostomias having strong spiral ribs, the spaces between which are ornamented by numer-
ous fine, raised, axial threads.
[S. D.J Odostomia (Oscilla) sequisculpta Carpenter.
Plate I, Figs. .^ and 3a.
Odostomia ( Evalea) cequisculpta Cpr., Ann. Mag. Nat. Hist., 3d Ser., Vol. XIV, 1864, pp. 46, 47.
Shell small, quite solid, elongate-ovate, subdiaphanous to white; nuclear whorls three,
obliquely one-third immersed; post-nuclear whorls rounded, separated by a prominent suture and
ornamented by about five fairly strong and rounded, subequally spaced spiral ridges on the second,
and six above the periphery on the penultimate whorl; the base of the last whorl is similarly sculp-
tured, the striations becoming fainter near the columella; the depressed spaces between the revolving
ridges are beautifully, closely crossed by fine axial riblets; periphery of the last whorl well rounded;
aperture large and effuse at base, posterior angle acute, outer lip thin, somewhat arcuate; columella
stout, provided with a small fold near the umbilical chink; a faint callus unites the posterior angle of
the aperture with the upper end of the columella; the external sculpture is apparent within the aper-
ture by transmitted light.
Dimensions. — Long. 2 mm.; diam. 1.2 mm.
The specimen here described and figured is Dr. Carpenter's type. It was
collected at Cape St. Lucas, Lower California.
This species occurs quite abundantly as a recent form, ranging from San
Pedro, California, to Ca2)e St. Lucas. It is also found in the post-Pliocene deposits
of San Diego.
The type is an immature specimen. One specimen comprising seven post-
nuclear whorls measures: long. 5 mm.; diam. L8 mm.
AKNOLD — THE PALEONTOLOGY AND STKATIGEAPHY OF SAN PEDKO. 285
[S. D.] Odostomia (Oscilla) grammatospira D. I- B., sp. nov.
Plate I, Figs. 6 and 6a.
Shell elongate-conic, subdiaphanous to milk white; nuclear whorls three, one-half obliquely
immersed; post-nuclear whorls flattened, traversed by four very strong, flattened, decidedly raised
spiral ridges, which are separated by furrows of about the same width ; the sutures being marked
by a little wider groove than those between the spiral ridges; the spiral depressions are very finely
and closely axially ribbed; the base of the last whorl is ornamented by similar sculpture, but of a
weaker character, the spiral ridges diminish gradually in size and at the same time approach each
other more closely, vanishing altogether on the extreme base; aperture subrhombic, posterior angle
acute, outer lip thin, arcuate, very much produced and flaring at the junction with the pillar; colu-
mella stout, reflexed, provided with a prominent fold at its insertion.
Dimensions. — Long. 5.3 mm.; diam. 2.1 mm.
The ty2:)e has eight post-nuclear whorls. It was collected at Cape St. Lucas,
Lower California. Two fossil specimens in our collection from the post-Pliocene
beds of San Diego are referable to this species.
Subgenus Ivara D. & B. (mss.)
Odosfomias characterized by the spiral striation and tabulated whorls.
305. Odostomia (Ivara) terricula (Carpenter) D. £■ B.
Plate IV, Fig. 14.
Ivara terriada Cpr. (mss.), D. & B., 1901.
Shell minute, ovate, thin; spire elevated; ape.x acute; whorls five, convex, shouldered above;
surface sculptured by fine, spiral ridges and obsolete transverse ribs, more prominent near top of
whorls; suture deeply impressed; body- whorl over half length of shell; shouldered above, evenly
convex below; aperture truncated above, evenly rounded below; outer lip thin, extending around and
up on columella, forming a small columellar plication.
Dimensions. — Long. 4 mm.; lat. 1.8 mm.; body-whorl 2.6 mm.; aperture 1.5 mm.
This delicate little shell is easily recognized by its shouldered whorls and
delicate spiral sculpture. Specimen identified by Dr. Dall; but the species omitted
from the text prepared by Dall and Bartsch.
Rare in lower San Pedro series of Deadman Island. One specimen, which is
figured, and is now in the collection of Delos Arnold.
Living. — Mexican Coast (Dall).
Pleistocene. — San Pedro (Arnold).
Superfamily T.^NIOGLOSSA.
Family LXV. TRITONID.E.
Genus Tritonium Link.
Shell oblong; spire prominent; whorls with a few remote and non-continuous varices; colu-
mella rough or smooth; canal recurved, short or long; outer lip internally crenated or denticulated.
Tritonium variegatus Lam. is a characteristic species.
286 CALIFORNIA ACADEMY OF SCIENCES.
306. Tritonium gibbosus Broderip.
Triton gibbosus Brod., Proc. Zool. Soc, 1833, p. 7, P). VII. Kuster, Conch. Cab., p. 69, fig. 7.
Tryon, Man. Conch., Vol. Ill, p. 23, PI. XII, fig. 103, 1881. Cooper, Bull. No. 4,
Cal. St. Min. Bureau, Part III, 1894, p. 32.
Shell small, subfusiform; whorls five, subtriangular, strongly angulated, giving tabular
ap[)earance to the upper part of whorls; prominent rounded, nodose varices at about every two-
thirds of a revolution, with two or three nodes on angle of whorl in intervening spaces; suture reaching
nearly to columella, giving a staircase appearance to the spire; surface ornamented with small,
revolving ridges made rugose by incremental lines; aperture subcircular; outer lip slightly corru-
gated internally; inner lip smooth, incrusted; canal long, narrow, curved slightly back; umbilicus
subperforate.
Dimensions. — Long. 41 mm.; lat. 22 mm.; body-whorl 28 mm.; aperture 10 mm.; canal
II mm.; defl. 56 degrees.
A unique shell, the only one of its genus so far recorded as occuring fossil in
California.
Rare in upper San Pedro series of San Pedro; one specimen found. Dr.
Dall also reports one found in the bay at this place, which he thinks is a fossil that
had been weathered out of the Pleistocene beds.
Living. — West tropical America; Panama (Cooper).
Pleistocene. — San Pedro (Dall; Arnold).
Subgenus Priene H. d- A. Adams.
Shell ventricose, thin, cancellated or plicated ; canal short ; operculum with apical
initial point.
307. Tritonium (Priene) oregonensis Redfidd.
Plate VI, Fig. 1.
Triton oregonetrse Kedf., Ann. N. Y. Lye, Vol. IV, 1846, p. 165, PI. XI, figs. 2a, 2b. Gld.,
Wilkes' Expl. Exped., Vol. XII, p. 241, 1852.
Fusus oregonensis Redf., Reeve, Icon. Conch., No. 61, figs. 6ia-d, 1848.
Triton (Priene) oregonensis Redf., Cpr., Brit. Assn. Rept., 1863, p. 66r.
Tritonium (Priene) oregonensis Redf., Gabb, Pal. Cal. Vol. II, p. 73, 1869.
Tritonium oregone7ise Redf., Dall, Proc. U. S. Nat. Mus., Vol. IX, 1887, p. 212.
Priene oregonensis Redf., Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 261. Keep, West Coast
Shells, p. 44, 1892.
Priene cancellatus Lam. {fide Tryon, Man. Conch., Vol. Ill, p. 34, PI. XVI, figs. 164-167;
PI. XVII, figs. 170-172, 1881) (pars).
Shell large, fusiform; spire elevated; apex blunt; whorls eight to ten, convex; nuclear
whorls smooth, except for obsolete spiral striations; cancellated sculpture of nearly equally promi-
nent spiral and transverse rounded ridges; suture deeply impressed; discontinuous rounded varices
at every half to two-thirds revolution on upper whorls; aperture subovate; outer lip not thickened,
slightly effuse on adult shells; canal long, narrow, recurved; inner lip incrusted; columella slightly
twisted; umbilicus obsolete.
Dimensions. — Long. 103 mm.; lat. 48.5 mm.; body- whorl 71 mm.; aperture 31 mm.; canal
21 mm.; defl. 47 degrees.
ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 287
Young shells look much like certain species of Triton on account of varices.
Common in the Pliocene of Deadman Island; rarer in the lower San Pedro series at
Deadman Island, and only occasionally found in the upper San Pedro series at
Deadman Island, San Pedro, and Crawfish George's. The specimen figured is from
tlie Pliocene of Deadman Island, and is now in the collection of Delos Arnold.
Living. — Straits of Fuca to Monterey; Japan (Cooper): dredged off San
Diego (Raymond): Kodiak Island (Snodgrass).
Pleistocene. — Santa Barbara; San Pedro (Cooper): San Pedro (Arnold).
Pliocene. — San Pedro (Arnold).
Genus Ranella Lamarck.
Shell ovate or oblong, compressed, with two rows of continuous varices, one on each side;
aperture oval; columella arcuated and ridged, or crenulated; canal short, recurved; outer lip
crenated.
Ranella spinosa Lam. is a characteristic species.
308. Ranella calif ornica Hinds.
Rayiella califoryiica Hds., Ann. Nat. Hist., Vol. II, 1843, p. 255; Voyage Sulphur, p. 12, PI. II,
figs. 3 and 5, 1S44. Cpr., Brit. Assn. Rept. , 1863, p. 661. Tryon, Man. Conch.,
Vol. Ill, p. 40, PI. XXI, fig. 32; PI. XXII, fig. 42, 1881. Gabb, Pal. Cal., Vol. II, p. 73,
1869. Keep, West Coast Shells, p. 44, fig. 24, 1892. Williamson, Proc. U. S. Nat.
Mus., Vol. XV, 1892, p. 211.
Shell large, broadly fusiform; spire elevated, about one-half length of aperture; whorls five,
convex, each with two prominent, rounded, rather reflexed varices, each set forming a continuous
varix from apex to base; between varices are one or two prominent rows of rounded nodes, each
row having from one to four, and numerous rugose revolving ridges of varying prominence; suture
deeply impressed, distinct; aperture subovate; outer lip thickened, ridged, denticulated; inner lip
incrusted, the spiral ornamentation sometimes showing through the incrustation; columella curved,
flattened, widened ; canal short.
Dimensions. — Long. 90 mm.; lat. 67 mm.; body-whorl 70 mm.; aperture, including canal,
53 mm.; defl. 76 degrees.
This shell is easily distinguishable by its size and general solid appearance.
Rare in the upper San Pedro series of San Pedro; three perfect specimens found;
one fine specimen from the upper San Pedro series of Los Cerritos; also found at
Deadman Island and Crawfish George's in the same horizon. Found in the Pleis-
tocene at Pacific Beach, San Diego.
Living. — Santa Barbara to Lower California (Carpenter).
Pleistocene. — Santa Barbara; San Pedro (Gabb): San Pedro; San Diego
(Arnold).
Pliocene. — Kirker's Pass.
288 CALIFORNIA ACADEMY OF SCIENCES.
Family LXVI. CYPR.EID.E.
Genus Cypr£ea Linne.
Shell ventricose, convolute, covered with shiny enamel; spire concealed; aperture long and
narrow, with a short canal at each end; inner lip crenulated; outer lip inflected and crenulated.
Cyprcea argus Linn, is a characteristic species.
309. Cypraea spadicea Gray.
Cypraa spadicea Swainson, Tillock's Phil. Mag., Vol. LXI, 1823, p. 376; E.xotic Conchology,
PI. CLXXXII. Tryon, Man. Conch., Vol. VII, p. 182, Pi. XIII, fig. 78, 1885.
Cypma spadicea Gray, Monog. Cyprseidea, Zool. Jour., London, Vol. I, 1824, p. 71. Dall,
Proc. U. S. Nat. Mus., Vol. XV, 1S92, p. 207.
Luponia spadicea Gray, Cpr., Brit. Assn. Rept., 1863, p. 657. Keep, West Coast Shells, p. 59,
fig- 43. 1892.
Luponia spadicea Swain., Gabb, Pal. Cal., Vol. II, p. 78, 1S69. Cooper, 7th Ann. Rept. Cal. St.
Min., 1888, p. 247.
Shell of medium size, pyriform, ventricose, convolute; spire concealed; surface covered
with shining reddish brown enamel in living shell (in the fossil obtained at San Pedro this is worn
and subdued); aperture long and narrow, with a short canal at each end, the anterior canal being the
longer; outer lip inflected and crenulated; inner lip crenulated.
DimensioJis. — Long. 50 mm. ; lat. 33 mm.; altitude, when lying aperture down, 25 mm.
Specimen identified by Dr. Dall.
One specimen from the upper San Pedro series of Deadman Island found by
Mrs. Oldroyd, and one from the upper San Pedro series at the lumber yard, San
Pedro, found by Delos Arnold.
Living. — Santa Barbara to San Diego and Lower California (Cooper).
Pleistocene. — Santa Barbara Island (Cooper) : San Pedro (Oldroyd; Arnold).
Genus Trivia Gray.
Small shells with striae extending over the back, where they are frequently interrupted by an
impressed dorsal sulcus.
Trivia quadripunctata Gray is a characteristic species.
310. Trivia californica Gray.
Trivia calif ornica Gra.y,CT'R., Brit. Assn. Rept., 1863, p. 657. Keep, West Coast Shells, p. 60,
figs. 44, a, b, 1892. WiLLi.\MSON, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 207.
Shell small, semiglobular; convex surface crossed by eight or nine transverse ridges, which
are interrupted on the center of the shell by a slight depression running longitudinally; sloping
surface of ends ornamented with several ridges that radiate from the ends of the dorsal depression;
aperture narrow, curved; outer and inner lip denticulated by elongated, sharp teeth, the continua-
tions of the transverse ridges.
Ditnensions. — Long. 8 mm.; lat. 6.5 mm.; alt. 5 mm.
ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 289
Only a few specimens fonnd in the upper San Pedro series of San Pedro.
Living. — Santa Bai-bara to Lower California (Carjjenter).
Pleistocene. — San Pedro (Arnold).
311. Trivia solandri Gray.
Trivia so/andri Gk\^, Cpr., Brit. Assn. Rept., 1863, p. 657. Keep, West Coast Shells, p. 60, 1892.
Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 207.
Shell, small, ventricose, convolute; spire concealed; about thirteen elevated lines cross the
back of the shell; these lines are interrupted in the middle of the shell by an impressed median
sulcus, along the sides of which the transverse lines end in rounded nodes; the sulcus does not
e.xtend to either end of the shell; aperture long and narrow, with a canal at each end; inner lip
crenulated; outer lip inflected and crenulated.
Ditnensions. — Long. 12.5 mm.; lat. 9.5 mm.; heigiit, when lying on aperture, 7 mm.
This species is distinguishable from T. californica by its much larger size,
coarser sculpture and impressed median sulcus.
One specimen from the lower San Pedro series of Deadman Island.
Living. — Santa Barbara to Panama (Carpenter).
Pleistocene. — San Pedro (Arnold).
Genus Erato Risso.
Shell obovate, polished; spire short, conical, distinct; aperture linear; outer lip without
varix, but thickened toward the middle, and denticulated within; columella with distinct plates at
the forepart.
Erato Icevis Donov. is a characteristic species.
312. Erato columbella Menke.
Erato coluinbeHa M.KE. , Zeit. Mai., p. 183, No. 26, 1847. Cpr., Brit. Assn. Rept., 1863, p. 657.
Tryon, Man. Conch., Vol. V, p. 10, PI. IV, fig. 8, 1883. Keep, West Coast Shells,
p. 61, fig. 46, 1892. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 240. William-
son, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 207.
Shell small, pyriform; spire only slightly elevated; whorls four, nearly flat, except body-
whorl, which is ventricose and pyriform, and comprises most of the shell; surface smooth; suturp
distinct; aperture long, narrow, curved around body-whorl; outer lip finely dentate within.
Dimensions. — Long. 7 mm.; lat. 4 mm.; body-whorl 6.5 mm.; aperture 6 mm.
One specimen from upper San Pedro series of San Pedro.
Living. — Monterey to San Diego; Mazatlan (Cooper).
Pleistocene. — Santa Barbara (Cooper): San Pedro (Arnold).
( 37 ) April 26, 1903.
290 CALIFORNIA ACADEMY OF SCIENCES.
Family LXVII. TRIFORID.E.
Genus Triforis Be^ihayes.
Shell sinistral, sculptured, granular; whorls numerous, terminating below in a small aper-
ture, with tubular anterior canal; opposite this canal is sometimes a second one upon a varix,
marking the position of a former aperture.
Iriforiti perversus Linn, is a characteristic species.
313. Triforis ad versa Montagu.
Triforis adversa Mont., Test. Brit., p. 271, 1803. Cpr., Brit. Assn. Rept., 1863, p. 660. Tryon,
Man. Conch., Vol. IX, p. 187, PI. XXXIX, fig. 51, 1887. Keep, West Coast Shells,
p. 47, 1892.
Shell sinistral, with cancellated sculpture, caused by three spiral and numerous equally as
prominent transverse ridges; resembles Bittiiim rugatum somewhat in sculpture.
One imperfect specimen from lower San Pedro series at Deadman Island
collected by Mrs. Oldroyd.
Living. — Vancouver to Santa Barbara Island (Carpenter).
Pleistocene. — San Pedro (Oldroyd).
Superfamily CERITHIACEA.
Family LXVIII. CERITHIOPSID.E.
Genus Seila A. Adams.
Shell spiral, elongated, many whorled, frequently varicose; aperture channeled in front,
with a less distinct canal posteriorly; outer lip not reflected; nuclear whorls sinistral; trans-
versely Urate.
314. Seila assimilata C. B. Adams.
Plate IV. Fio. 8.
Ccriihiopsis assimilata C. B. Ad., Maz, Cat., No. 563, 1852. Cpr., Brit. Assn. Rept.. 1863. p. 660.
Tryon, Man. Conch., Vol. IX, p. 174, PI. XXXVI, fig. 59, 1887. Cooper, 7th Ann.
Rept. Cal. St. Min., 1888, p. 232. Keep, West Coast Shells, p. 48, 1892.
Shell small, thin, turreted; nuclear whorls sinistral; whorls ten, ornamented with three
prominent, sharp, equal, equidistant, raised spiral lines; interspaces between ridges crossed by
numerous fine lirulae; suture indistinct, not distinguishable on upper portion of spire; base truncated
abruptly, flat; aperture subquadrate; outer lip thin, not effuse; inner lip simple; columella recurved;
canal short.
Dimensions. — Long. 10 mm.; lat. 3.8 mm.; body-whorl 3.8 mm.; aperture 2.1 mm.; defl.
24 degrees.
Resembles the Bittinm?., bnt is distino-iiishable by the strong spiral linos.
Specimen identified by Dr. Dall. Rare in lower San Pedro series at San Pedro.
ARNOLD— THE PALEONTOLOGY AND STIUTIGRAPHY OF SAN PEDRO. 291
The specimen figured was obtained from the lower San Pedro series at San
Pedro, and is now in the private collection of Delos Arnold.
Living. — Monterey to Panama (Cooper): Catalina Island, 20 fathoms
(Arnold, 1901).
Pleistocene. — San Pedro (Oldroyd; Arnold): San Diego (Cooper).
Family LXIX. CERITHllDiE.
Genus Bittium Leach.
Shell elevated, with numerous granular whorls and irregular varices; anterior canal short,
not recurved; inner lip simple; outer lip not reflected, usually with an exterior rib.
Bittium reticulatum Da Costa is a characteristic species.
315. Bittium asperum Gabb.
Turbonilla aspera Gabb, Proc. Phil. Acad. Nat. Sci., 1861, p. 368.
Bittium asperum Gabb, Cpr., Ann. & Mag. Nat. Hist., 3rd Sen, Vol. XVII, 1866, p. 276. Gabb,
Pal. Cal., Vol. II, p. 72, PI. II, fig. 20, 1869. Tryon, Man. Conch., Vol. IX, p. 153,
PI. XXX, fig. 7, (887. Cooper, 7th Ann. Kept. Cal. St. Min., 18S8, p. 230.
Bittium asperum Cpr., Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 205.
Shell small, slender, turreted; ape.x elevated, acute; whorls nine to ten, nearly flat on
posterior portion, with prominent angulation anteriorly; sculpture consists of three spiral ridges,
crossed by sixteen to eighteen much more prominent ridges; suture deep, distinct; aperture semi-
elliptical, with prominent basal emargination instead of a canal; lip thin, inner side crenulated; body-
whorl angulated, base slightly sculptured spirally.
Dimetisions. — Long. 10.5 mm.; lat. 31 mm.; aperture 2.5 mm. x 1.5 mm.; defl. 22 degrees.
This species may be distinguished by the relative prominence of its trans-
verse sculpture. Specimens identified by Dr. Dall
Common in the Pliocene at Deadman Island and Timm's Point; rare in the
lower San Pedro series of Deadman Island, and found only occasionally in the upper
San Pedro series of Crawfish George's and San Pedro. Found in the Pleistocene at
bath-house, Santa Barbara; at Barlow's ranch, Ventura; and at Pacific Beach,
San Diego.
Living. — Santa Barbara to Catalina Island (Cooper).
Pleistocene. — Santa Barbara to San Diego (Cooper): San Pedro; Ventura;
Santa Barbara; San Diego (Arnold).
Pliocene. — San Diego well (Dall): San Pedro (Arnold).
316. Bittium californicum Dall & Bartsch.
Pl.\te IV, Fig. 4.
Bittium {E/ac/iista) californicum. Dall & Bartsch, Nautilus, Sept., 1901, p. 58.
Shell, small, thin, white, turreted; spire elevated, mammilliform ape.x; whorls eight, convex,
slightly more angular on anterior portion of whorl; whorls crossed by twelve or thirteen prominent.
292 CALIFORNIA ACADEMY OF SCIENCES.
rounded, equal, equidistant ridges; spiral sculpture hardly visible; suture deeply impressed, distinct;
aperture subrotund; outer lip thin, smooth; columella smooth; body-whorl angulated at the base;
base shows spiral lines.
Diinensions. — Long. 6 mm.; lat. 2.2 mm.; body-whorl 2.5 mm.; aperture i mm.; defl.
24 degrees.
This species, with the possible exception of B. ivilliajnsoni, is the smallest of
the Pleistocene BiUiiims of this locality, and is easily distingui.shable by its size and
the faintness of its spiral sculpture. Several specimens show a slightly le.ss deflection
than the one figured. Specimen identified by Dr. Dall.
Rare in the lower San Pedro series at San Pedro. The specimen figured,
which was found in the lower San Pedro series at San Pedro, is now in the collec-
tion of Delos Arnold.
Pleistocene. — San Pedro (Arnold).
317. Bittium filosum Gould.
Cerithium filosum Gld., Proc. Bost. Soc. Nat. Hist., Vol. Ill, 1849, p. 120; Wilkes' Expl. Exped.,
Vol. XII, p. 149, fig. 175, 1852.
Bittium filosmn Gld.. Cpr., Brit. Assn. Rept., 1863, p. 655. Tryon, Man. Conch., Vol. IX,
p. 152, PI. XXIX, fig. 90, 1887. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 230.
Keep, West Coast Shells, p. 72, fig. 57, 1892.
Shell small, slender, turreted; apex elevated, acute; whorls eight, flat, slightly angulated
near anterior margin, and ornamented with four alternating ridges and grooves of about equal width;
apical whorls transversely sculptured; base of body-whorl sculptured in same way; suture deep,
distinct; aperture small, semielliptical, with basal emargination instead of a canal; lip thin, with
interior ridges corresponding to exterior grooves.
Dimensions. — Long. 8.5 mm.; lat. 2.9 mm.; aperture 2 mm. x 1.2 mm.; defl. 20 degrees.
This species is distinguishable by its lack of transverse ornamentation. The
specimen described was identified by Dr. Dall.
Specimens of this sjjecies are rather rare in both the lower and upper San
Pedro series at San Pedro and Deadman Island; a few found at Crawfish George's.
Living. — Sitka to Monterey (Cooper).
Pleistocene. — Santa Barbara (Cooper): San Pedro (Arnold).
318. Bittium quadrifilatum Carpenter.
Plate IX, Fig. 2.
BittiMfn quadrifilaiurn Cpr., Brit. Assn. Kept., 1863, p. 655; Jour, de Conch., Vol. XII, 1865, p. 143.
Tryon, Man. Conch., Vol. IX, p. 153, PI. XXIX, fig. 91, 1887. Cooper, 7th Ann.
Rept. Cal. St. Min., 1888, p. 230. Keep, West Coast Shells, p. 72, 1892. William-
son, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 205, PI. XXI, fig. 4.
Shell small, turreted, elongate; apex acute; whorls ten or eleven, nearly flat; body-whorl
slightly ventricose; surface sculptured by four more or less prominent spiral ridges, and on upper
whorls by transverse ridges; these ridges become obsolete on the penultimate and body-whorls in
adult specimens, leaving only the spiral lines on these whorls; suture distinct, impressed, giving a
AENOLD — THE PALEONTOLOGY AND STKATIGRAPHY OP SAN PEDRO. 293
keeled appearance to the lower portion of the whorl in some specimens; aperture subquadrate; outer
lip thin; columella Truncate, spirally sculptured without.
Dhnensions. — Long. lo mm.; lat. 2.5 mm.; defl. 18 degrees.
This species is intermediate between B. filosum and B. asperum, having the
sculpture of the former on the body-whorl and the sculpture of the latter on the
apical whorls, while the intermediate whorls have a gradation sculpture. Speci-
mens identified by Dr. Dall.
Not uncommon in the lower San Pedro series at Deadman Island and San
Pedro; rare in the upper San Pedro series at Deadman Island, San Pedro, Los
Cerritos, and Crawfish George's. Found in the Pleistocene at the bath-house, Santa
Barbara.
The specimen figured is from the lower San Pedro series at Deadman Island,
and is now in the collection of Delos Arnold.
Living. — Monterey to San Diego (Cooper).
Pleistocene. — Santa Barbara (Cooper): San Pedro; Santa Barbara (Arnold).
One of the laws of evolution is that of acceleration of development, which has
been formulated by Alpheus Hyatt,' as follows: —
"All modifications and variations in progressive series tend to appear first in
the adolescent or adult stages of growth, and then to be inherited at earlier and
earlier stages, according to the law of acceleration, until they either become embry-
onic or are crowded out of the organization, and replaced in the development by
characters of later origin."
This means that theoretically each organism in its ontogeny, or life history,
ought to go through stages of growth corresponding to all of its ancestors, and that
these stages ought to appear in the order of its ancestral forms. This law is exempli-
fied by the genetic series, consisting of B. asperum, B. quadrifilatum and B. filosum.
First, we have B. asperum, which is the only species of this genus found in
the Pliocene at Deadman Island. It has a characteristic nodose-cancellate sculpture,
caused by two series of ridges, spiral and transverse, and this sculpture extends back
from the body-whorl through the intermediate to the apical whorls. Thus, in this
species the same characteristic sculpture is found in the larval stage (which is rep-
resented by the apical whorls), the adolescent stage (intermediate whorls), and in the
adult stage, which is represented by the penultimate and body-whorls.
Next we have B. quadrifilatum (Plate IX, fig. 2), which is first found in
the lower San Pedro beds of the Pleistocene, and which, it is reasonable to suppose,
developed out of Bittium asperum. At any rate, this species is not found in the
Pliocene, but is quite abundant in the lower San Pedro. The sculpture of this
species is as follows: Apical whorls nodose-cancellate; intermediate whorls with the
transverse sculpture becoming less prominent as the whorls become larger; penulti-
mate and body-whorl generally with four prominent spiral threads or ridges, but with
1 A. Hyatt, "Genesis of the ArietidEe," Preface, p. ix.
294
CALIFOENIA ACADEMY OF SCIENCES.
transverse sculpture obsolete. It is thus seen that the nsperum sculj^ture is found in
the intermediate and apical whorls. That is, the cancellate sculpture, or, more prop-
erly speaking, the transverse sculpture, has been gradually forced back toward the
earlier stages of growth, and is wholly lost in the adult stages of B. quadrifilatum.
The next species in the series is B. filosum. This species is found very
sparingly in the lower San Pedro, and although not common in the upper San Pedro,
is noticeably more abundant in this later horizon than in the one preceding. Its
separation from B. quadrijilatum no doubt began early in the Pleistocene, but this
type did not reach a full development until the time of the upper San Pedro. The
sculpture of this species consists primarily of spiral ridges or raised lines. This to the
naked eye seems to be the only sculpture in typical specimens, but with the aid
of a microscope the apical whorls are seen to have quite prominent transverse ridges,
giving them (with the spiral ridges) a cancellate or asperam sculpture. Thus we see
that the sculpture developed in the adult B. a^perum is forced out of the adult stages
and back into the adolescent stages, while in B.Jilosum we have the same sculpture
occurring only in the apical whorls, or larval stage. As the larval period is the
earliest in which we may study the shell of the gastropod, we may reasonably suppose
that in the next marked period of development this cancellate sculpture would be
completely lost, leaving only the typical B.Jilot^um, or spiral sculpture, to ornament
the whole shell from its larval to its adult stage, unless new characteristics of
sculpture were developed in the meantime.
The spiral sculpture has been the persistent character in this series, while the
transverse has been nearly lost by being forced back further and further toward the
embryonic stage in succeeding individuals, until we have it remaining only in the
very earliest whorls of B.Jilosuni.
It is true that all three of these species are living at the present day, and that
the transverse sculpture has persisted in certain individuals up to the present time,
but they are sufficiently differentiated to call by different specific names. It is
evident that in the case of the Biitluvis under discussion, the development of what
we call species has been brought about, not so much by the acquiring of certain
specific characteristics, as by the gradual loss of a certain characteristic already
possessed by the ancestral form.
TABLE SHOWING DEVELOPMENT OF SCULPTURE.
Larval stage, apical
Adolescent stage, in-
Adult stage, penultimate
whorls.
termediate whorls.
and body-whorl.
B. filosum. (Upper San Pedro)
spiral and weak
transverse.
spiral.
spiral.
B. quadrijilatum (Lower San Pedro) .
spiral and trans-
spiral and weak
spiral.
verse.
transverse.
B. aspenim (Pliocene)
spiral and trans-
spiral and trans-
spiral and transverse.
verse.
verse.
AKNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 295
319. Bittium rugatum Carpenter.
Plate IV, Fig. U.
Biltium rugatum CpR., Ann. & Mag. Nat. Hist, 3rd Ser., Vol. XVII, 1866, p. 276.
Shell small, turreted; spire elevated; apex acute; whorls ten to eleven, flat; numerous trans-
verse ridges, crossed by a varying number of nearly equally prominent spiral ridges, produce a
nodose-cancellated sculpture; the spiral ridges increase in number on the anterior whorls; suture
very deeply impressed, forming a sutural canal; body-whorl angulated, base ornamented with fine
spiral and transverse lines; aperture subrectangular; outer lip thin, smooth; columella incrusted;
canal short.
Dimensions. — Long. 13 mm.; lat. 5 mm.; body-whorl 6 mm.; aperture 3.5 mm.; defl.
23 degrees.
Thi.s species is quite variable in sculpture, owing to the varying number of
spiral ridges on different individuals. The specimen described was identified by
Dr. Dall.
Common in the lower San Pedro series at Deadman Island and San Pedro,
and in upper San Pedro series at Deadman Island, Crawfish George's, Los Cerritos,
and San Pedro. The specimen figured is from the upper San Pedro series at San
Pedro, and is now in the collection of Delos Arnold.
Living. — Catalina Island to San Diego (Cooper).
Pleistocene. — Santa Barbara to San Diego (Cooper): San Pedro (Arnold).
320. Bittium v^illiamsoni, sp. nov.
Plate VI, Fig. 11.
Shell small, elongate, turreted; whorls seven, angular, flat and sloping above, straight
below; upper surface of whorl minutely cancellate with fine spiral and transverse ridges; lower sur-
face with two prominent spiral ridges and faint transverse ribs; suture deeply impressed, distinct;
aperture circular; base smooth; basal angle rounded slightly.
Dimensions. — Long. 2.5 mm.; lat. i mm.
This is the smallest of the Bitluims found in the San Pedro deposits, and is
distinguishable by its small size, prominently turbinated apex, and prominent can-
cellated sculpture. The specimen figured is the type, which was identified as a new
species by Dr. Dall, and which is now in the United States National Museum.
Found in the upper San Pedro series of San Pedro. Also found in the
Pleistocene at Spanish Bight, near San Diego.
Living.— [Vbi?) (Dall).
Pleistocene. — San Pedro (Arnold).
Subgenus Styliferina A. Adams.
Diaphanous; conical turreted; whorls smooth, convex; apex mucronate; aperture subquad-
rate; inner lip straight.
Bittium orthochila A. Ads. is a characteristic species.
296 CALIFORNIA ACADEMY OF SCIENCES.
321. Bittium (Styliferina) tenuisculpta Carpenter.
Plate VI, Fig. 14.
Shell small, conical, turreted, thin, diaphanous; apex sharp; whorls ten, rounded, nearly
smooth, but showing faint spiral sculpture; suture deep, distinct; body-whorl evenly rounded below;
aperture subrotund; outer lip thin; inner lip simple.
Dimensions. — Long. 5 mm.; lat. 2 mm.; body-whorl 2.5 mm.; aperture 7.5 mm.; defl.
20 degrees.
Specimens identified by Dr. Dall.
Rare in lower San Pedro series of San Pedro; one specimen found, which is
figured, and is now in the collection of Delos Arnold.
Living. — West Coast (?).
Pleistocene. — San Pedro (Arnold).
Genus Diastema Deshayes.
Shell turreted; whorls with numerous transverse ribs, and with a few intermediate varices;
inner margin of the aperture partially detached from the previous whorl; the aperture itself is
strongly contracted posteriorly.
322. Diastema, sp. indet.
Shell small, regularly conical, turreted; whorls seven, convex, ornamented with eleven
slightly oblique transverse ridges, which are most prominent on the angle of the whorl and become
obsolete at the sutures; suture deeply impressed; aperture broadly elliptical; outer lip thin; inner lip
smooth; canal short.
Dime)isions. — Long. 10.5 mm.; lat. 4.5 mm.; body-whorl 5.8 mm.; aperture, 4 mm.; defl.
28 degrees.
The above description was taken from a shell which Dr. Dall pronounced a
young of the genus Diasioma.
Lower Pleistocene of San Pedro, only one specimen. A specimen of the
same species (?) was found in the Pleistocene at the bath-house, Santa Barbara.
Pleistocene. — San Pedro; Santa Barbara (Arnold).
Genus Cerithidea Stvainson.
Shell turriculated, longitudinally ribbed; whorls numerous; summit of spire more or less
decollated; aperture rounded, slightly slit anteriorly; outer lip expanded, thickened, broadly rounded
below, and usually produced into a beak crossing the sinus to the left.
Cerithidea decollatum Linn, is a characteristic species.
323. Cerithidea calif ornica Haldemann.
Cerithinm californiciim Hald., Fr. W. Univ. Moll., cover of No. I, 1840.
Cerithium (^Potamis) sacratum Gv-D., Proc. Bost. Soc. Nat. Hist., Vol. \\\, 1849, p. 118; Wilkes'
Expl. Exped., Vol. XII, p. 114, PI. X, fig. 116, 1852. Tryon, Man. Conch.,
Vol. IX, p. 162, PI. XXXIII, figs. 69-72, 1887.
ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 297
Ceri/hidea sacrata G'L'D.,CvvL.,Y'roc. Zool. Soc, 1S56, p. 226. Keep, West Coast Shells, p. 71,
fig. 56, 1S92.
Cerithidea californica Hald., Gabb, Pal. Cal, Vol. II, p. 79, 1869. Cooper, 7th Ann. Rept. Cal.
St. Min., 1888, p. 233. Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 2, 1892, p. 277.
Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1S92, p. 205.
Shell turreted; ape.x decollated; whorls nine or ten, slightly convex, ornamented with three
or four spiral ridges and numerous transverse ridges, the two sets varying in prominence; suture
impressed, distinct; aperture subquadrate; outer lip effuse, thickened, broadly rounded below, and
slightly produced in a columellar beak; inner lip straight above this beak.
Dimensions. — Alt. 25 mm.; lat. 9.5 mm.; defl. 22 degrees.
This is the only representative of this genus, and is one of the commonest of
the gastropods in the ujiper San Pedro formation.
Found in the Pliocene of Deadman Island, lower San Pedro series of Dead-
man Island and San Pedro, and upper San Pedro series of Crawfish George's, Los
Cerritos, San Pedro, and Deadman Island. Found in the Pleistocene at Twenty-
sixth Street and Pacific Beach, San Diego.
Living. — Paulinas Bay to San Diego; Mazatlan (Cooper).
Pleistocene. — San Pedro to San Diego (Cooper): San Pedro; San Diego
(Arnold).
Pliocene. — San Fernando, Los Angeles County (Cooi:)er) : San Pedro (Arnold).
Family LXX. C^CID^.
Genus Caecum Fleming.
Young shell spiral in one plane, afterwards an arcuated tube, truncated posteriorly by the
loss of the spiral portion, and closed there by a convex septum or plug.
CdBGum cornv.oides is a characteristic species.
324. Cgecum californicum Dull.
Plate VIII, Fig. 6.
CcBcum cooperi CvR., Brit. Assn. Rept., 1863, p. 655; not of Smith {Jide Dall).
Cceciwi californicum Dall, Proc. U. S. Nat. Mus., Vol. VIII, 1885, p. 541. Tryon, Man. Conch.,
Vol. VIII, p. 219, PI. LXVI, fig. 65, 1886. Keep, West Coast Shells, p. 73, 1892.
Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 2, 1892, p. 299.
Shell small, tubular, curved, white, very slightly tapering; plug bent toward conve.x side;
aperture circular, slightly contracted; surface ornamented by thirty to forty prominent, narrow,
rounded rings.
Ditnensions.- — Long, (maximum) 3 mm.; lat. 0.9 mm.
Shell may be distinguished from C. crebricinctum by its small size and much
more prominent, narrow, sharp rings.
Quite common in the upper San Pedro series of San Pedro and Crawfish
George's, and in the lower San Pedro series of Deadman Island and San Pedro.
( 38 ) April 27, 1903.
298 CALIFORNIA ACADEMY OF SCIENCES.
The specimen figured is from tlie lower San Pedro series at Deadman Island, and is
now ill the collection of Delos Arnold.
Living. — Santa Barbara Island to Sau Diego (Carpenter): Catalina Island,
20 fathoms (Arnold, 1901).
Pleistocene. — San Pedro (Arnold): San Diego (Stearns).
Pliocene. — Sau Quentin Bay, Lower California (Orcutt).
325. Ceecum crebricinctum Carpenter.
Plate VIII, Fig. 10.
CcEcnm crebj-icindum CvK. , Brit. Assn. Rept. , 1863, p. 655; Proc. Cal. Acad. Sci., Vol. Ill, 1865,
p. 215. Tryon, Man. Conch., Vol. VIII, p. 218, PI. LXVII, fig. 71, 18S6. Keep,
West Coast Shells, p. 73, 1892. Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 2,
1892, p. 300. Williamson, Proc. U. S. Nat. Mus. , Vol. XV, 1892, p. 204.
Shell small, white, curved, tubular, thin; ornamented with very fine, close, annular ring
sculpture; plug subangulate, bent toward convex side.
Dimensions. — Long. 5.5 mm.; lat. i mm.
Distinguishable from C. californicum by its larger size and less prominent
rings. The specimen described was identified by Dr. Dall.
Found in the lower San Pedro series of Deadman Island and San Pedro, and
in the upper San Pedro series of San Pedro and Crawfish George's. The specimen
figured is from the lower San Pedro series at San Pedro, and is now in the collection
of Delos Arnold.
Living. — Monterey to San Diego (Carpenter): San Pedro (Williamson):
Catalina Island, 20 fathoms (Arnold, 1901).
Pleistocene. — San Pedro (Arnold): San Diego; Coronado Beach (Dall).
Pliocene. — San Quentin Bay, Lower California (Orcutt).
326. Caecum magnum Stearns.
Plate VIII, Fig. 16.
CcEcummagnum Stearns, Tryon, Man Conch., Vol. VIII, p. 219, Pis. LXVII, LXXXTII, 1886.
Shell small, tubular, curved, tapering; surface sculptured with numerous fine rings; aperture
circular; plug sharp.
Dimensions. — Long. 5 mm.; latitude, base, 0.9 mm.; apex 0.3 mm. «
This species resembles C. crebricinctum, but differs from that species in being
more curved and in tapering much more rapidly from the anterior to the posterior
extremity. Specimen identified by Dr. Dall. Tryon's figure may be of C. crebri-
cinctum. One specimen from the lower San Pedro series of Deadman Island, which
is figured, and is now in the collection of Delos Arnold.
LAving. — ?
Pleistocene. — San Pedro (Arnold).
ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 299
Family LXXI. VEEMETIDiE.
Genus Serpulorbis Sassi.
Shell tubular, irregularly twisted, adherent; aperture rounded ; columella not plicate.
Serpulorbis arenaria Quoy. is a characteristic species.
327. Serpulorbis squamigerus Carpenter.
Aleles squamigerus Cpr., Proc. Zool. Soc. , 1856, p. 226.
Serpulorbis squamigerus Cpr., Brit. Assn. Rept. , 1863, p. 654. Cooper, 7th Ann. Rept. Cal. St.
Min., 1888, p. 264. Keep, West Coast Shells, p. 74, 1892. Williamson, Proc. U. S. Nat.
Mus., Vol. XV, 1892, p. 204.
Vermetus squatnigerus CpR., Tryon, Man. Conch., Vol. VIII, p. 181, PI. LIV, figs. 73, 74, 1886.
Shell tubular, irregularly twisted, adherent; surface may be transversely or longitudinally
ornamented, generally, however, only showing circular incremental lines; aperture circular.
Dimensio7is. — Diameter from 2 mm. to 15 mm.
In some cases found attached to rocks in conglomerate, in others found in
irregular aggregates or individual sections.
Common in the upper San Pedro series of San Pedro and vicinity; rare in
the lower San Pedro series of Deadman Island and San Pedro. Found in the
Pleistocene at Pacific Beach, San Diego.
Living. — Monterey to San Diego (Cooper).
Pleistocene. — Santa Barbara to San Diego (Cooper): San Pedro; San Diego
(Arnold).
Subgenus Vermicularia Lamarck.
328. Serpulorbis (Vermicularia), sp. indet.
One small nepionic shell of a species of this genus was found in the lower
San Pedro series of San Pedro. Specimen identified by Dr. Dall.
Pleistocene. — San Pedro (Arnold).
Genus Spiroglyphus Daudin.
Animal forming a groove on the surface of shells or stones, covering it over with shelly
matter, and forming a tubular case.
Spiroglyphus sj)i7'orbis Dillw. is a characteristic species.
329. Spiroglyphus lituella Morch.
Siphoniuni {Dendropoma') lituella Morch., Proc. Zool. Soc, 1861, p. 154.
Spiroglyphus lituella Morch., Cpr., Brit. Assn. Rept., 1863, p. 654. Keep, West Coast Shells,
p. 73, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 204.
Shell small, irregularly and sometimes openly spiral, rather compressed; color dingy white;
surface sculptured by incremental lirulai and arcuate striae, which are approximately regular;
aperture circular.
Dimensiotts. — Diameter of coil 1.5 mm.
300 CALIFORNIA ACADEMY OF SCIENCES.
This little animal forms a groove on the surface of shells or stones, and covers
it over with shelly matter, forming a tubular case.
Common on stones and shells of upper San Pedro series at San Pedro.
Deadman Island, Crawfish George's, and Los Cerritos.
Living. — California coast (Carpenter).
Pleistocene. — San Pedro (Arnold).
Family LXXII. TURRITELLID^.
Genus Turritella Lamarck.
Shell elongated; many whorled; whorls rounded, with revolving striae; aperture rounded.
2urritella terebra Linn, is a characteristic species.
330. Turritella cooperi Carpenter.
Turritella cooperi Cpr., Brit. Assn. Rept., 1863, p. 655; Proc. Cal. Acad. Sci., Vol. Ill, 1864,
p. 216. Gabb, Pal. Cal., Vol. II, p. 80, 1869. Tryon, Man. Conch., Vol. VIII, p. 20,
PI. LXI, 1886. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 269. Keep, West
Coast Shells, p. 73, fig. 58, 1892. Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 2,
1892, p. 318. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 205.
This species is distinguishable from T. jercettii by its deeply impressed and
distinct suture, faint spiral ridges (lacking entirely in some sjiecimens), circular
aperture, and sharper spire, the deflection in this species being only 10 degrees.
Resembles Atlantic form, 2\ apicalii^.
Rather common in the Pliocene and Pleistocene of San Pedro and vicinity.
Found in the Pliocene at Pacific Beach and Russ School, San Diego; and in the
Pleistocene at Pacific Beach, San Diego; and at Barlow's ranch and the irrigating
ditch, Ventura.
Living. — Santa Barbara to San Diego (Coojier).
Pleistocene. — Santa Barbara to San Diego (Cooper): San Pedro; San Diego;
Ventura (Arnold).
Pliocene. — San Diego well (Dall): San Pedro; San Diego (Arnold): San
Quentin Bay, Lower California (Orcutt).
331. Turritella jewettii Carpenter.
Plate IV, Fig. 13.
Turritella je^wettii Cpr., Brit. Assn. Rept., 1863, p. 655; Ann. & Mag. Nat. Hist., 3rd Sen,
Vol. XVII, 1866, p. 276. Gabb, Pal. Cal., Vol. II, p. 80, 1869. Cooper, 7th Ann.
Rept. Cal. St. Min., 1888, p. 269.
? Turritella sanguinea Reeve, Cooper (Williamson), Bull. No. 4, Cal. St. Min. Bureau, 1894,
Part 3, p. 32.
ARNOLD — THE PALEONTOLOGY AND STEATIGRAPHY OF SAN PEDRO. 301
Shell turreted, with slender, tapering spire; number of whorls variable; whorls flat, with two
distinct spiral ridges on anterior portion and three or four less distinct ridges posteriorly; incremental
lines distinct and concave anteriorly; suture thread-like and rather indistinct, not usually impressed;
aperture angular.
Dimensio7is. — Defl. i6 degrees.
The spiral sculpture in this species is quite variable, the prominence of the
various ridges not being constant; the suture is also somewhat impressed in some
specimens. A more solid shell than T. conperi, being less slender, having more
prominent spiral sculpture, a more angular aperture and a less distinct suture than
the latter species. The shell listed by Mrs. Williamson as T. sanguinea from the San
Pedro Pleistocene is probably this species, as Carpenter in his original description
(the tyjie being a Pleistocene fossil from Santa Barbara) says that T. jewetiii is near
T. sanguinea.
Common in the Pliocene, rarer in the lower San Pedro series, and still rarer in
the upper San Pedro series of San Pedro and vicinity. The specimen figured is from
the Pliocene of Deadman Island, and is now in the collection of Delos Arnold.
Pleistocene. — Santa Barbara to San Diego (Cooper): San Pedro (Arnold).
Pliocene. — San Diego well (Dall) : San Pedro (Arnold).
Family LXXIII. LITTORINID^.
Genus Littorina Ferussac.
Shell turbinated, thick, pointed, few-vvhorled; aperture rounded; outer lip acute; columella
rather flattened, imperforate.
Littorina litorea Linn, is a characteristic species.
332. Littorina planaxis {Nuttall) Philippi.
Littorina plajiaxis Nutt., Philippi, teste Cpr., Proc. Zool. Soc, 1856, p. 266. Cpr., Brit. Assn.
Rept., 1863, p. 655. Gabb, Pal. Cal., Vol. II, p. 80, 1869. Tryon, Man. Conch.,
Vol. IX, p. 24S, PI. XLIII, figs. 55, 56; PI. XLIV, fig. 57, 1887. Cooper, 7th Ann.
Rept. Cal. St. Min., 1888, p. 246. Keep, West Coast Shells, p. 68, fig. 53, 1S92.
=L. pattila Gld. {fide Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 2, 1892, p. 321).
Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 205.
Shell small, broadly conical; spire not much elevated; whorls three, convex, the last being
ventricose; surface roughened by lines of growth; aperture ovate; outer lip thin; inner lip and
columella flattened and effuse.
DimensioJis. — Alt. 8 mm.; lat. 6.2 mm.; aperture 5 mm. x 3.5 mm.; defl. 70 degrees.
Distinguishable from L. scutulata by lack of coloration, rough surface, very
effuse inner lip, greater deflection, and fewer whorls. Specimens identified by
Dr. Dall.
One specimen each, from the upper San Pedro series of San Pedro, and
302 CALIFOENIA ACADEMY OF SCIENCES.
lower San Pedro series of Deadman Island; found also in the lower San Pedro
series at San Pedro; and in the Pliocene of Deadman Island.
Living. — Sitka; San Diego (Cooper).
Pleistocene. — San Nicolas Island; San Diego (Cooper): San Pedro (Arnold).
333. Littorina scutulata Gould.
Littoritia scutulata Gld., Proc. Bost. Soc. Nat. Hist., Vol. Ill, 1849, p. 83; Wilkes' Expl. Exped.,
Vol. XII, p. 200, fig. 241, 1852. Cpr., Brit. Assn. Rept., 1863, p. 656. Tryon, Man.
Conch., Vol. IX, p. 250, PI. XLV, figs. 98-103, 1887. Cooper, 7th Ann. Rept. Cal.
St. Min., 1888, p. 246. Keep, West Coast Shells, p. 68, fig. 52, 1892. Williamson,
Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 205.
Littorina plena Gld., Proc. Bost. Soc. Nat. Hist., Vol. Ill, 1849, p. 84; Wilkes' Expl. Exped.,
Vol. XII, p. 201, fig. 236, 1852.
Shell small, conical; spire elevated, subacute; whorls four, very slightly convex, the last one
ventricose and slightly angulated; sculpture consists of numerous nearly obsolete, spiral striae, and
fine, oblique, incremental lines; aperture ovate; outer lip thin, lower part effuse; inner lip incrusted,
effuse; color reddish brown.
Dimensions. — Alt. 10 mm.; lat. 6 mm.; aperture 5 mm. x 3 mm.; defl. 48 degrees.
All the specimens from the Pleistocene that have been examined show a
characteristic reddish brown color. Several specimens identified by Dr. Dall; among
them two which were marked "variety," but which have been included in this species
for lack of constant varietal differences.
Found in the lower San Pedro series at Deadman Island and San Pedro; and
in the upper San Pedro series at Los Cerritos, Crawfish George's, San Pedro, Long
Beach, and Deadman Island. Found in the Pleistocene at Barlow's ranch, Ventura;
and at Pacific Beach and Spanish Bight, San Diego.
Living. — Monterey to San Diego (Cooper).
Pleistocene. — San Pedro to San Diego (Cooper): San Pedro; Ventura; San
Diego (Arnold).
Genus Lacuna Turton.
Shell turbinated, thin; aperture semilunar; columella flattened, with an umbilical fissure.
Lacuna pallidula Da Costa is a characteristic species.
334. Lacuna compacta Carpenter.
Lacuna ? var. compacta Cpr., Brit. Assn. Rept., 1863, p. 656.
Lacuna {? solidiila, var. J compacta Cpr., Ann. & Mag. Nat. Hist., 3rdSer., Vol. XIV, 1864, p. 429.
Trvon, Man. Conch., Vol. IX, p. 266, PI. L, fig. 71, 1887.
Shell small, thin, compact; spire elevated, subacute; whorls four, slightly convex; body-
whorl prominently angulated at base; suture impressed, distinct; aperture ovate; outer lip not effuse^
thin; inner lip slightly effuse; chink very small, almost obsolete; surface faintly marked with very
fine incremental lines.
Dimensions. — Long. 6 mm.; lat. 4 mm.; ajierture 3 mm. .x 2 mm.; defl. 60 degrees.
ARNOLD — THE PALEONTOLOGY AND STEATIGEAPHY OF SAN PEDRO. 303
Distinguishable by its compactness, angulated body-whorl, small chink and
angle of deflection. The specimen described was identified by Dr. Dall as probably
being of this species.
Some specimens of L. compacta in the State Museum collection at Berkeley
are labeled L. solidula.
Rare in lower San Pedro series at Deadman Island; and in the upper San
Pedro series at Los Cerritos and San Pedro. Found in the Pleistocene at Barlow's
ranch, Ventura; at bath-house, Santa Barbara; and at Spanish Bight, San Diego.
Living. — Vancouver district (Carpenter).
Pleistocene. — San Pedro; Ventura; Santa Barbara; San Diego (Arnold).
335. Lacuna porrecta Carpenter.
Lacuna porrecta CpR., Brit. Assn. Rept, 1863, p. 656; Ann. & Mag. Nat. Hi.st., 3rd Sen, Vol. XIV,
1864, p. 429. Tryon, Man. Conch., Vol. IX, p. 265, PI. L, figs. 55, 56, 57, 1887.
Keep, West Coast Shells, p. 66, 1892.
Shell small, white; spire not much elevated; whorls three, convex; body-whorl very slightly
angulated; suture distinct; aperture ovate; lip effuse; umbilical chink large.
DimeJisions . — Long. 6 mm.; lat. 5 mm.; body-whorl 5.7 mm.; aperture 4.5 mm.; defl.
74 degrees.
Distinguishable by large umbilical chink, depressed spire, large angle at apex,
and effuse outer lip.
Three specimens of this species found in the lower San Pedro series at Dead-
man Island; also found in same horizon at San Pedro; and in the upper San Pedro
series at Deadman Island, San Pedro, Los Cerritos, and Crawfish George's.
Living. — Vancouver district (Carpenter).
Pleistocene. — San Pedro (Arnold).
336. Lacuna solidula (Loven) Carpenter.
Plate VIII, Fig. 11.
Lacjina solidula Loven, Index Moll. Scandin., p. 23 {teste Cpr., Brit. Assn. Rept., 1863, p. 656).
Gabb, Pal. Cal, Vol. II, p. 80, 1869. Tryon, Man. Conch., Vol. IX, p. 266, PI. L,
fig. 69, 1887. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 244. Keep, West
Coast Shells, p. 66, 1892. Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 2, 1892,
p. 321. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 205.
Lacuna carmata Gld., Proc. Bost. Soc. Nat. Hist., 1848, p. 75.
Liitorina pedroana Con., Pac. R. R. Rept, Vol. V, p. 327, PI. VI, fig. 50, 1S56.
Modelia striata Gab^, Proc. Phil. Acad. Nat. Sci., 1861, p. 368.
Shell small, turreted, thin; spire elevated, subacute; whorls four, rounded, ornamented with
fine oblique incremental lines; suture deeply impressed, distinct; aperture large, ovate; outer lip
thin; inner lip sharp, effuse, incrusted; small umbilical chink.
Dimensions. — Long. 10 mm.; lat. 6.2 mm.; body-whorl 7.5 mm.; aperture 5.5 mm. ; defl.
44 degrees.
304 CALIFOENIA ACADEMY OF SCIENCES.
Distinguishable from other members of tlie genus found in this formation by
its elevated spire, deeply impressed suture, and small deflection. The specimen
described was identified by Dr. Dall.
Rare in lower San Pedro series at Deadman Island and upper San Pedro
series at San Pedro. Found also in the Pleistocene at Pacific Beach, San Diego.
The specimen figured is somewhat decorticated, came from the upper San Pedro
series at San Pedro, and is now in the collection of Delos Arnold.
Living. — Alaska to San Diego (Cooper).
Pleistocene. — Santa Barbara to San Diego (Cooper): San Pedro; San
Diego (Arnold).
Family LXXIV. FOSSARID^.
Genus Fossarus Philippi.
Shell perforated, sculptured; inner lip thin; aperture semilunate.
Fossarus costatua Brocchi is a characteristic species.
Subgenus Isapis //. d- A. Adams.
Shell umbilicated; spire elevated; cancellated, or with revolving ribs; columella with a small
median tooth.
Isapis anomala C. B. Adams is a charactei'istic species.
337. Fossarus (Isapis) fenestrata Carpenter.
Isapis fenesh-ala Cpr., Brit. Assn. Rept., 1863, p. 656; Ann. & Mag. Nat. Hist., 3rd Ser., Vol. XV,
1865, p. 28. Keep, West Coast Shells, p. 65, 1892. Williamson, Proc. U. S. Nat.
Mus., Vol. XV, 1892, p. 206.
Shell small, turreted; spire elevated, subacute; whorls four, slightly convex, ornamented
with prominent, squarish, raised, spiral ridges, with numerous fine, oblique liruLe in the interspaces;
three spiral ridges on penultimate whorl, twelve to thirteen on body-whorl; suture deeply impressed,
distinct; aperture ovate; outer lip thin, slightly effuse; inner lip flattened, effuse; umbilical
chink small.
Dimensions. — Long. 8 mm.; lat. 7 mm.; body-whorl 7 mm.; aperture, 5 mm.; defl.
65 degrees.
Found in the lower San Pedro series of Deadman Island and San Pedro, and
in the upper San Pedro series at Crawfish George's, San Pedro, and Deadman Island.
Living. — Vancouver to San Diego (Carpenter).
Pleistocene. — San Pedro (Arnold).
Family LXXV. RISSOID^.
Genus Rissoa Freminville.
.Shell minute, white or horny; conical pointed, many-whorled; smooth, ribbed or cancel-
lated; aperture rounded; peristome entire, continuous; outer lip slightly expanded, thickened.
Pissoa costulata Risso is a characteristic species.
ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 305
338. Rissoa acutelirata Carpenter.
Plate IV, Fio. \2.
Rissoa acutelirata Cpr., Brit. Assn. Rept., 1863, p. 656.
Shell minute, conical, pointed, rather thick; whorls five, convex, with fifteen sharp, distant,
spiral riblets, traveling over eighteen sharp distant ribs, which are obsolete on base of body-whorl;
aperture ovate; peristome entire, continuous.
Dimensions. — Long. 1.5 mm.
This minute little shell is seen under the microscope to have a very cancellated
sculpture. Specimens identified by Dr. Dall.
Rare in upper San Pedro series of San Pedro. Two specimens. Found also
in the Pleistocene at the old irrigating ditch, Ventura. The specimen figured is
from the upper San Pedro series at San Pedro, and is now in the collection of
Delos Arnold.
Living. — San Diego (Carpenter).
Pleistocene. — -San Pedro; Ventura (Arnold).
Subfamily HYDROBIIN^.
Genus Paludestrina d'Orbigny.
Shell conical, more or less elongated; smooth, imperforate or nearly so; apex acute; aperture
ovate; peritreme continuous; outer lip acute; inner lip not thickened.
Paludestrina piscium d'Orbigny is a characteristic species.
339. Paludestrina curta, sp. no v.
Plate VIII, Fig. 2.
Shell small, conical, very thin; spire elevated; ape.x rounded; whorls four, very convex,
smooth, except for obsolete transverse sculpture; suture deeply impressed, distinct; aperture oval;
peritreme continuous, thin; umbilicus subperforate.
Dimensions. — Long. 4 mm ; lat. 2.2 mm.; body-whorl 2.6 mm.; aperture 1.5 mm.; defl.
38 degrees.
Distinguishable from P. stokesi by much broader shell, fewer whorls, and more
perforate umbilicus. Pronounced a new species by Dr. Dall.
Rare in lower and upper San Pedro series of San Pedro. The specimen
figured is the type, which is from the lower San Pedro series at San Pedro, and is
now in the United States National Museum.
Pleistocene. — San Pedro (Arnold).
340. Paludestrina stokesi, sp. nov.
Plate VIII, Fig. 3.
Shell small, conical, thin; spire elevated; apex acute; whorls six, very convex; surface with
faint, nearly obsolete, rounded, transverse ridges; suture deeply impressed, distinct; body-whorl
( 39 ) April 27, 1903.
306 CALIFORNIA ACADEMY OF SCIENCES.
evenly ventricose; aperture oval; peritreme continuous; outer lip acute; inner lip not thickened;
umbilicus nearly obsolete.
Dimejisions. — Long. 4.8 mm.; lat. 2 mm.; body-whorl 2.5 mm.; aperture i mm.; defl.
22 degrees.
This little fresh-water gastropod is distinguishable by its small size, thin shell,
very convex whorls and continuous peritreme. Specimens pronounced a new species
by Dr. Dall. Named in honor of Mr. Frank Stokes of Pasadena, California.
Rare in upper and lower San Pedro series of San Pedro. The specimen
figured is the type, which is from the lower San Pedro series at San Pedro, and is
now in the United States National Museum.
Pleistocene. — San Pedro (Arnold).
Family LXXVI. CALYPTRiEID.E.
Genus Crucibulum Schumacher.
Shell conical, more or less regular, with subcentral, subposterior, sharp apex; aperture basal,
with a central, internal, cup-shaped lamina, which is entire, and attached along a hue on one side to
the inner wall of the shell
Section Crucibulum, s. s.
Distinguished from Dispotcea by having in the adult the whole margin of the internal cup
free from|the shell, and the cup as a whole merely attached by a narrow strip of adhesion.
Crucibulum rudis Brod. is a characteristic species.
341. Crucibulum spinosum Sowerby.
CalyptrcEa spinosa Sby., Gen. of Shells, PI. XXIII, figs. 4, 7, 1824.
Criicibulum spinosmn Shy., Reeve, Icon. Conch., Sp. 10. Conrad, Pac. R. R. Rept., Vol. V,
p. 327, PI. V, fig. 46, 1856. Cpr., Brit. Assn. Rept., 1856, p. 323, PI. IX, figs. 3a, 3/;
id., 1863, p. 654. Gabb, Pal. Cal., Vol. II, p. 81, 1869; Geol. San Domingo, p. 241,
1873. Trvon, Man. Conch., Vol. VIII, p. 118, PI. XXXII, fig. 38, 1886. Cooper,
yth Ann. Rept. Cal. St. Min., 1888, p. 237. Keep, West Coast Shells, p. 77, fig. 62,
1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 203.
Crucibulum, auricula var. spinosum Shy., ^Dispotaa dumosa Con. (young shell), =Crucibi<lum
dumosum Tuomey & Holmes (young shell), {fide Dall, Trans. Wagner Inst. Sci.,
Vol. Ill, Part 3, 1892, p. 350.)
Shell conical, elevated; apex rather acute, slightly curved, smooth, subcentral; surface
ornamented with numerous rounded, radiating ridges, and sometimes with concentric rows of spires;
concentric lines of growth visible; a cup-shaped lamina is attached along a line on one side of the
interior of the shell; inner surface smooth; rim thin; aperture nearly circular.
Dimensions. — Diam. 21 mm.; alt. 13.5 mm.
The only member of this genus found in the San Pedro series of this locality.
Dr. Dall says that the recent specimens from California agree in the minutest par-
ticular with the Caloosahatchie fossils. This is probably a case of a survival of an
old form.
ARNOLD — THE PALEONTOLOGY AND STEATIGRAPHT OF SAN PEDRO. 307
Common in the lower San Pedro series of Deadman Island, and in upper San
Pedro series of Deadman Island, San Pedro, Los Cerritos, Long Beach, and Crawfish
George's. Found in the Pleistocene at Twenty-sixth Street and Pacific Beach,
San Diego.
Living. — Monterey to San Diego (Carpenter): south to Peru (Cooper).
Pleistocene. — Santa Barbara (Cooper): San Pedro; San Diego (Arnold).
Pliocene. — San Diego well (Dall): Caloosahatchie beds and Alligator Creek,
Florida (Dall and Willcox).
Miocene. — (Newer) North and South Carolina (Conrad and Holmes): (older)
San Domingo (Gabb).
Genus Galerus Humphrey.
Shell depressed, subcorneal, spiral; summit subcentral; aperture very large, basal, with a
subspiral broad lamina adhering to the left margin.
Galerus chinensis Linn, is a characteristic sjaecies.
342. Galerus mammillaris Broderip.
Galerus mamfni/laris Brod., Trans. Zool. Soc, 1835, PI. XXIII, fig. 5. Cpr., Brit. Assn. Rept.,
1856, p. 323. =^Calyptrea fastigiata Gld., = (?) Galerus contortus Cpr. {fide Dall,
Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 203).
Calyplrea tnamrtiillaris Brod., Trvon, Man. Conch., Vol. VIII, p. 120, PI. XXXIV, figs. 64-75,
78-81, 1886.
Shell depressed, subconical; whorls flattened, three; apex central, blunt; aperture subcircular,
large; a broad lamina begins at apex on inner surface and makes a whole turn to the left, reaching
nearly to margin; lower part of body-whorl corrugated; surface marked by irregular spiral striae.
Dimensions. — Long. 32 mm.; lat. 30 mm.; alt. 7 mm.
The specimen described was identified by Dr. Dall.
Rare in lower San Pedro series of Deadman Island and San Pedro; and in
the upper San Pedro series at Crawfish George's and San Pedro.
Living. — Puget Sound to Monterey (Cooper) : Santa Barbara to Central
America (Carpenter): San Pedro (Williamson).
Pleistocene. — San Pedro (Arnold).
Pliocene. — San Diego well (Dall).
Genus Crepidula Lamarck.
Shell oval, limpet-like, with a posterior, generally lateral spiral apex; interior with a shelly
lamina covering its posterior half
Crepidula peruviana Lam. is a characteristic species.
308 CALIFORNIA ACADEMY OF SCIENCES.
343. Crepidula aculeata Gmelin.
Patella aculeata Gmel., Syst. Nat., p. 3693, 1788.
Crepidula aculeata Gmel., ^Calyptraa echinus Brod., =Calyptma hystrix Brod., ^Crepidula
californica NuTT. (^fide Cpr., Brit. Assn. Rept., 1856, p. 323, PI. VIII, figs. 3a, 37).
Cpr., Brit. Assn. Rept., 1863, p. 654. Tryon, Man. Conch., Vol. VIII, p. 129,
PI. XXXIX, figs. 61-65, 1886. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 236.
Dall, Bull. U. S. Nat. Mus., No. 37, 1889, p. 152. Keep, West Coast Shells, p. 76,
1892. Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 2, 1892, p. 357. Williamson,
Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 203.
Shell small, deep, thin; apex near anterior margin curved to left, smooth; surface sculptured
with numerous prominent rounded, discontinuous, irregular ridges from near apex to margin; margin
thin, crenulated; aperture subquadrate; deck oblique, thin, cupped, lower on right side than on
left; inner surface smooth.
Dimensions. — Long. 11 mm.; lat. 9 mm.; alt. 6 mm.
The specimen described was identified by Dr. Dall. The occurrence of this
species on both sides of the American continent is probably due to the survival of
an old form which has changed little since the two regions were closely connected
by water.
Rare in the lower San Pedro series of San Pedro and Deadman Island.
Living. — Monterey, south; Asia; Atlantic (Cooper).
Pleistocene. — San Pedro to San Diego (Cooper): San Pedro (Arnold).
Pliocene. — San Fernando (Cooper) : De Leon Springs, Shell Creek, and
Alligator Creek, Florida (Dall and Willcox).
344. Crepidula adunca Sou-erhy.
Crepidula adunca Sby., Tank. Cat., Appen., p. 7, 1825. Cpr., Brit. Assn. Rept., 1863, p. 654.
Gabb, Pal. Cal., Vol. II, p. 82, 1869. Tryon, Man. Conch., Vol. VIII, p. 129,
PI. XXXVIII, figs. 51-55; PI. XXXVII, figs. 39, 40; PI. XXXIX, fig. 60, 1886.
Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 236. Keep, West Coast Shells.
P- 75' fig- 60, 1892. Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 2, 1892, pp. 355,
358. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 203.
Crepidula rostriformis Gld., Proc. Bost. Soc. Nat. Hist., Vol. II, 1846, p. 160; Wilkes' Expl.
Exped., Vol. XII, p. 375, fig. 482, 1852.
Crypta adunca Sby., H. & A. Adams, Gen. Rec. Moll., Vol. I, p. 369, 1853.
Shell nearly circular at base, elevated and curved backwards to apex; apex elevated, sharp,
hooked, and removed from margin; surface marked with fine lamellar lines of growth; aperture
nearly circular; margin thin; deck short, thin in middle, thicker towards sides, with anterior edge
deeply curved; cavity penetrates beak from deck; deck set deep in shell.
Dime7isio7is. — Long. 19 mm.; lat. 12.5 mm.; alt. 10.5 mm.; aperture 15 mm. x 12.5 mm.
This shell is easily distinguishable by its elevated apex and short, curved-edged
deck. Dr. Dall identified the shell described. This is the West Coast form of the
Atlantic G. convexa Sby.
Rather rare in the lower San Pedro series of Deadman Island and San Pedro;
and in the upper San Pedro series of Los Cerritos, Crawfish George's, San Pedro, and
AKNOLD— THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 309
Deadman Islaiul. Found in the Pleistocene at the bath-house, Banta Barbara; at
Barlow's ranch, Ventura; and at Spanish Bight, San Diego.
Living. — Straits of Fuca to Santa Barbara; Mexico (Cooper).
Pleistocene. — Santa Barbara; San Diego (Cooiier) : San Pedro; Santa Barbara;
Ventura; San Diego (Arnold).
345. Crepidula dorsata Broderip.
Crepidula dorsata Brod., Proc. Zool. Soc, 1834, p. 38. Cpr., Brit. Assn. Rept. , 1863, p. 654.
Gabb, Pal. Cal, Vol. II, p. 82, 1869. Tryon, Man. Conch., Vol. VIII, p. 127,
PI. XXXVII, figs. 26-30; PI. XXXVIII, fig. 41, 1886. Cooper, 7th Ann. Rept. Cal.
St. Min., 1888, p. 236. Keep, West Coast Shells, p. 76, 1892. Dall, Trans. Wagner
Inst, Sci., Vol. Ill, Part IV, 1892, p. 358.
Crypta dorsata Brod., H. & A. Adams, Gen. Rec. Moll., Vol. I, p. 369, 1853.
Shell small, much depressed; apex curved to one side and upward, smooth on tip; surtace
sculptured with rough, rounded, radiating ridges, expanding and also increasing in number by inter-
callation toward the margin; aperture round; margin crenulated and thickened; deck partly detached,
thin, oblique, with pit at apex.
Dimensio)is. — Diam. 10 mm.; alt. 3 mm.
Rare in the lower San Pedro series of Deadman Island; and upper San Pedro
series of Crawfish George's and Los Cerritos.
Living. — Straits of Fuca to Mazatlan; Peru, South America (Cooper).
Pleistocene. — Santa Barbara (Cooper): San Pedro (Arnold).
Pliocene. — San Fernando (Cooper).
346. Crepidula grandis Middendorff.
Crepidula grajidis Midd., Mai. Ross., Part II, p. loi, PL XI, figs. 8, 9, 10, 1849. Cpr., Brit.
Assn. Rept., 1863, p. 584. Gabb, Pal. Cal., Vol. II, p. 81, 1869. Tryon, Man.
Conch., Vol. VIII, p. 127, PI. XXXVII, fig. 33, 1886. Cooper, 7th Ann. Rept. Cal.
St. Min., 1888, p. 237. Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part II, 1892,
P- 358.
Shell heavy, elevated obliquely fi^om an oval base; sides flattened; apex narrowed, curving
nearly to side margin; surface sculptured by numerous fine lamellar lines of growth; deck long,
thick (much thicker on side opposite from apex) and showing lines of growth on inner side, occupies
over half of aperture, joins shell near margin.
Dimensioyis. — Long. 80 mm.; lat. 50 mm.; alt. 45 mm.; aperture 60 mm.
The rim, especially near the posterior end, shows the lamellar structure of the
shells. These shells have a very jironounced habit of growing one upon another
until the group sometimes numbers six or eight individuals. This species is easily
recognized by its size and thickness.
Dr. Dall unites C. prcerupta Con. and C. princeps Con., but sejaarates this
species from C. grandis Midd. It has been the writer's privilege to examine quite a
series of C. prcerupta Con. from the Astoria Miocene of Blakeley, Washington, and
310 CALIFORNIA ACADEMY OF SCIENCES.
it is his opinion, also, that this species is distinct from C. grandis. Two specimens in
the upper San Pedi'o series of Deadman Island. Found also in the Pliocene at
Pacific Beach, San Diego.
Living. — Kamtschatka; Hakodate, Japan; Okhotsk (Carpenter).
Pleistocene. — Santa Barbara (Cooper): San Pedro (Arnold).
Pliocene. — Santa Rcsa; 'Kirker's Pass; Santa Barbara; San Fernando; San
Diego well (Cooper): Alpine Creek, San Mateo County; Stanford University; San
Diego (Arnold).
Miocene — Toraales, Marin County; Walnut Creek, Contra Costa County;
Foxin's and Santa Rosa Island, Santa Barbara County (Cooper).
347. Crepidula navicelloides Nutiall.
Crepidula navicelloides Nutt., Jay's Cat., No. 3035, 1835. Cpr., Brit. Assn. Rept., 1863, p. 654.
Gabb, Pal. Cal., Vol. II, p. 82, 1869. Tryon, Man. Conch., Vol. VIII, p. 126, 1886.
Cooper, 7th Ann. Rept., Cal. St. Min., 1888, p. 237. Keep, West Coast Shells, p. 76.
fig. 61, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 203.
Crepidula nummaria Gld., Proc. Best. Soc. Nat. Hist., Vol. II, 1846, p. 60; Wilkes' Expl. Exped.,
Vol. XII, p. 377, fig. 480, 1852.
Crepidula explatiata Old., Mex. and Cal. Shells, p. 4, PL XIV, fig. 7, 1853; Proc. Zool. Soc, 1856,
p. 205.
This shell varies greatly in shape, due to the surface on which it grows.
Specimens .showing an easy gradation from the circular, flat variety, (7. nummaria,
through the typical, oblong, flat, C. navicelloides, to the elongated, curved variety,
C. explanata, have been found in the upper San Pedro series of San Pedro. This
species may be distinguished from the other members of this genus by its flat or
dorsally concave appearance, and by the way in which the deck is raised in the
center to allow body space between it and the inner surface of the shell. Repre-
sentatives of the above forms were identified by Dr. Dall as this species.
Rare in the lower San Pedro series of Deadman Island; and in the upper San
Pedro series of Crawfish George's, Los Cerritos, San Pedro, and Deadman Island.
Found also in the Pleistocene at the bath-house, Santa Barbara.
Living. — Alaska to San Diego (Cooper).
Pleistocene. — Santa Barbara (Cooper): San Pedro; Santa Barbara (Arnold).
Pliocene.- — San Diego well (Dall).
348. Crepidula onyx Sowerhy.
Crepidida onyx Sby., Genera of Shells, No. 23, fig. 2, 1824. Cpr., Proc. Zool. Soc, 1856, p. 225;
Brit. Assn. Rept, 1856, p. 323. Tryon, Man. Conch., Vol. VIII, PI. XXXVII, fig. 37;
PI. XXXVIII, figs. 43-50; Pi. XXXIX, fig. 59, 1886.
Shell ovate, generally irregular, low arched, strong; apex small, marginal, sharp and turned
to one side; surface marked by concentric lamellar lines of growth; aperture irregularly ovate; rim
ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 311
thin; interior reddish brown (shows in all Pleistocene specimens examined), except for border equal
in width to the space between the deck and the rim, which is light colored; deck thin, with nearly-
straight edge; slight depression where deck joins shell on right side; deck curves upward at margin
where it joins shell, making the line of contact indistinct in most specimens, the deck merging
into the shell.
Diniensions. — Long. 32 mm.; lat. 25 mm.; alt. 10 mm.
This shell may be distinguished from C. rugoaa by its larger size, depressed
form, interior coloration, and by the indistinctness of the line of contact between the
deck and the shell. The deck of C. onyx is also joined to the shell nearer the rim
than is the deck of either C. rugosa or C. adunca.
This specimen was identified by Dr. Dall.
Rare in the lower San Pedro series of Deadman Island and San Pedro; and
in upper San Pedro series of Deadman Island, Los Cerritos, and San Pedro. Found
also in the Pleistocene at Spanish Bight and Pacific Beach, San Diego.
Living. — Panama, Central America (Carpenter).
Pleistocene. — San Pedro; San Diego (Arnold).
349. Crepidula rugosa Nidtall.
Crepidula rugosa Nutt., mss., Proc. Zool. Soc. , 1856, p. 224. Cpr., Brit. Assn. Rept., 1863, p. 654.
Tryon, Man. Conch., Vol. VIII, p. 128, PL XXXVII, fig. 37, 1886. Keep, West
Coast Shells, p. 76, 1892.
Crepidula onyx Sby. var. rugosa Nutt., Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 203.
Shape of shell similar to C. onyx, but more arched; apex prominent, submarginal, sharp,
hooked, smooth, turned only slightly to one side; lines of growth irregular; surface rugose, and
quite glossy in some specimens; aperture oval; margin thin; deck deeply sunken in shell, and line
of contact with shell very distinct; edge of deck straight.
Dimensions. — Long. 20 mm.; lat. 12 mm.; alt. 10 mrn.; aperture 15.5 mm. x 12 mm.
Distinguishable from G. onyx by more prominent apex, which is further from
the margin than in the latter; by the deeper set deck and by the less prominent
lines of growth. Smaller than C. onyx. This specimen was identified by Dr. Dall.
Found in lower San Pedro series of Deadman Island and San Pedro; and in
the upper San Pedro series of Crawfish George's, Deadman Island, San Pedro, Los
Cerritos, and Long Beach.
Living. — Santa Barbara to San Diego (Cooper): Mexico to Peru ? (Cooper).
Pleistocene. — Santa Barbara to San Diego (Cooper): San Pedro (Arnold).
Family LXXVII. AMALTHEID^.
Genus Hipponyx De France.
Shell thick, obliquely conical, non-spiral; apex somewhat posterior and curved backwards;
muscular impression horseshoe-shaped; base of attachment shelly, secreted by the foot of the animal.
Hipponyx cornucopice Lam. is a characteristic species.
312 CALIFORNIA ACADEMY OF SCIENCES.
350. Hipponyx antiquatus Linnceus.
Patella anfiquaius Linn., Syst. Nat., Ed. XII, p. 1259, 1768. Dillw., p. 1035, No. 44, 1760.
Hipponyx antiquatus Yat^ia., Menke, Zeit. f. Mai., p. 79, 1853. Cpr., Proc. Zool. Soc, 1856, p. 3;
Brit. Assn. Rept., 1863, p. 654. Tryon, Man. Conch., Vol. VIII, p. 134, PI. XL,
figs. 93-99, 1886. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 244. Keep,
West Coast Shells, p. 74, fig. 59, 1892.
Concholepas antiquatus Linn., H. & A. Adams, Gen. Rec. Moll, Vol. I, p. 373, 1853.
Shell obliquely conical; ape.x blunt, projecting beyond posterior margin of shell; surface
roughened by prominent lamellar, concentric lines of growth; base ovate; rim smooth, not crenated.
This is a very variable species, the specimen described having an unusuall}'
elevated apex. The specimen was identified by Dr. Dall.
Carj)enter believes the Hippony.v mitrula of the West Indian fauna to be
identical with the Bipponyx antiquatus of the Pacific Panama region. If these two
are identical it is another case of an old species which has lived on in both habitats,
having changed but little since the two regions were connected by water; or else it
is a case of parallel development, where two species, having come from a common
stock and living among like conditions, though separated geograjjhically, have
developed along parallel lines and are enough alike at the present time to warrant
their being called the same species. In such a genus as Hipponyx, where there are
so many mutations in a single species, either case would be possible.
One specimen from the lower San Pedro series of Deadman Island; also found
in the Pliocene of Deadman Island.
Living. — Bodega Bay and south; South America; Atlantic (Cooper).
Pleistocene- — San Pedro (Cooper; Arnold).
351. Hipponyx cranioides Carpenter.
Hipponyx cranioides Cpr., Ann. & Mag. Nat. Hist., 3rd Sen, Vol. XIII, 1863, p. 428. Tryon,
Man. Conch., Vol. VIII, p. 135, PL XL, figs. 6, 7, 1886. Cooper, 7th Ann. Rept.
Cal. St. Min., 1888, p. 244.
Shell obliquely conical, depressed; apex inconspicuous, blunt, posterior to center, but not
reaching margin; surface ornamented with several wide lamellae of growth which are grooved by
numerous radiating furrows; aperture ovate; rim thin, sometimes corrugated near outer edge;
interior smooth.
Dimensions. — Long. 19 mm.; lat. 17 mm.; alt. 6 mm.
Distinguishable from H. antiquatus by depressed shell, more central apex,
and more regular lamellae of growth, which are prominently radially furrowed. The
specimen described was identified by Dr. Dall.
According to Tryon H. tumens equals H. cranioides.
Rather common in the lower San Pedro series at Deadman Island and San
Pedro; rare in upper San Pedro series at Deadman Island and LosCerritos. Found
also in the Pleistocene at Spanish Bight, San Diego.
Living.- — ^Straits of Fuca to Santa Barbara (Cooper).
Pleistocene. — Santa Barbara (Cooper): San Pedro; San Diego (Arnold).
ARNOLD — THE PALEONTOLOGY AND STKATIGEAPHY OF SAN PEDRO. 313
352. Hipponyx turnens Carpenter.
Hipponyx turnens CPR., Brit. Assn. Rept., 1863, p. 654; Ann. & Mag. Nat. Hist., 3rd Ser.,
Vol. XV, 1865, p. 181.
Capulus tiimens Cpr., Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 232.
Shell of medium size, tumid, with oval base; apex distinct, small, sharp, curved to right
side, raised above margin; surface sculptured by numerous sharp, distinct, raised radiating lines and
less prominent lines of growth, which give the radiating lines a slightly granulose appearance;
aperture oval, slightly effuse, and finely crenulated on outer border.
Dimensions. — Long, (including apex) 11.5 mm.; Jat. 10 mm.; alt. 5 mm.
Distinguishable from H. antiquatus by its rather faint, regular sculpture, of
which the radiating lines are much more prominent than the concentric.
One specimen from the lower San Pedro series of Deadman Island; also found
in lower San Pedro series at San Pedro; and in the upper San Pedro series at Dead-
man Island. Found also in the Pleistocene at Pacific Beach, San Diego.
Living. — Monterey to San Diego and Islands (Cooper).
Pleistocene. — San Pedro (Cooper; Arnold): San Diego (Arnold).
Family LXXVIII. NATICID^.
Genus Natica {Adanson) Scopoli.
Shell subglobular; spire slightly elevated; aperture half round; a spiral columellar callus
entering the umbilicus.
Nation canrena Linn, is a characteristic species.
Subgenus Cryptonatica Ball.
Naticas with smooth calcareous operculum and an umbilicus entirely and smoothly filled
with callus.
Type, Natica claiisa Brod. & Sowb.
353. Natica (Cryptonatica) clausa Broderip & Sowerby.
Plate X, Fig. 13.
Natica clausa Brod. & Sby., Zool. Jour., Vol. IV, 1829, p. 360; Zool. Beechey's Voyage, p. 136,
PI. XXXIV, fig. 3; PI. XXXVII, fig. 6, 1839. Cpr., Brit. Assn. Rept., 1863, p. 661.
Gabb, Pal. Cal., Vol. II, p. 77, 1869. Tryon, Man. Conch., Vol. VIII, p. 30, PL IX,
figs. 65, 67-69, 73, i886. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 253. Keep,
West Coast Shells, p. 46, 1892.
Natica russa Gld., Proc. Bost. Soc. Nat. Hist., Vol. VII, 1859, p. 43; Otia, p. 109, 1862. Cpr.,
Brit. Assn. Rept., 1863, p. 586. Cooper, Bull. No. 4, Cal. St. Min. Bureau, Part 3,
1894, p. 29.
Shell of medium size, ovate-globular; spire only slightly elevated; whorls four, evenly
convex, though sometimes slightly shouldered; surface smooth except for fine incremental lines;
( iO ) April 28, 1903.
314 CALIFORNIA ACADEMY OF SCIENCES.
suture impressed, distinct; aperture semilunar; outer lip sharp; inner lip callous and reflected
completely over the umbiHcus.
Dimensions. — Alt. 27 mm.; lat. 25 mm.; aperture 20 mm. x 12.5 mm.; defl. 115 degrees.
After comparing a series of Naticas collected from the Pliocene of Deadman
Island, part of which were identified as N. russa and part as N'. clausa by Dr. Dall,
it is very evident that there is no difference between the two species. This species
is distinguishable from Neverita reduziana by a more elevated spire, more evenly
convex whorls, and a more concave umbilical region.
Rare in Pliocene of Deadman Island and Timm's Point. None have been
found in the Plei.stocene by the writer, except one small specimen which came from
the lower San Pedro series at Deadman Ishind. Found in the Pliocene at Packard's
Hill, and in the Pleistocene at the bath-house, Santa Barbara. The specimen
figured is a medium sized one from the Pliocene of Deadman Island, and is now in
the collection of Delos Arnold.
Living. — Arctic Ocean; Alaska; North Atlantic (Cooper).
Pleistocene. — Santa Barbara to San Diego (Cooper): San Pedro; Santa
Barbara (Arnold).
Pliocene. — San Pedro; Santa Barbara (Arnold).
Genus Polynices Mont fort.
This group includes all of the Naticidte with corneous opercula.
Type, Natica mnmmilla Linn.
Subgenus Neverita Risso.
Shell depressed, orbicular; spire conical or flattened; columella partly filled by a tongue-
shaped callous process (funiculum) from the columella. Operculum horny.
Natica duplicata Say is a characteristic species.
354. Polynices (Neverita) recluziana Petit.
Platk X, Fig. 1-2.
Natica recluziana Petit, Deshaves, Mag. de ZooL, Mollusca, p. 37, 1841. Tryon, Man. Conch.,
Vol. VIII, p. 34, Pi. XII, fig. I, 1886.
Neverita recluziana Petit, H. & A. Adams, Gen. Rec. Moll., Vol. I, p. 208, 1853. Cpr., Brit.
Assn. Rept., 1863, p. 661. Cooper, 7th Ann. Rept. Cal. St. Min., i888, p. 254.
Keep, West Coast Shells, p. 46, fig. 26, 1892. Williamson, Proc. U. S. Nat. Mus.,
Vol. XV, 1892, p. 211.
Neverita recluziana Desh., Gabb, Pal. Cal., Vol. II, p. 77, 1869. Dall, Trans. Wagner Inst. Sci.,
Vol. Ill, Part 2, 1892, p. 369.
Shell ovate to flattened globular; spire only very slightly elevated, obtuse; whorls three,
slightly convex; body-whorl having a long, slightly convex slope fi-om suture to near base, where it
AKNOLD — THE PALEONTOLOGY AND STKATIGEAPHY OF SAN PEDEO. 315
suddenly turns under to umbilicus; surface ornamented with fine, oblique incremental lines; suture
distinct, but not impressed; aperture semilunar; lip thin; columella incrusted, the incrustation
extending down and completely covering the umbilicus.
Dimensions. — Long. 20 mm.; lat. 24 mm.; aperture 16 mm. x 10 mm.; defl. 130 degrees.
(A rather small specimen.)
The young shells are more depressed than the adults, .some of them being
quite flat. In some of the specimens the callus has not completely covered the
umbilicus, leaving a little pit near the lower part of the umbilical region. This
species is very variable in both size and shape. Dr. Dall has described a variety
with an elevated spire which he calls var. alia. This variety is quite common in all
of the upper San Pedro series localities.
Common in the upper San Pedro series of the San Pedro region, but rare in
the lower San Pedro series and Pliocene. Found in the Pleistocene at Barlow's
ranch and old irrigating ditch, Ventura; at Spanish Bight, Twenty-sixth Street, and
Pacific Beach, San Diego; and in the Pliocene at Pacific Beach, San Diego. The
specimen figured is from the upper San Pedro series at San Pedro, and is now in the
collection of Delos Arnold.
Living. — Monterey to Lower California (Cooper).
Pleistocene. — Santa Barbara to San Diego (Cooper) : San Pedro; Santa
Barbara; San Diego (Arnold).
Pliocene. — Santa Barbara; San Fernando (Cooper) : San Pedro; San Diego
(Arnold): San Diego well (Dall).
Miocene. — Martinez; Walnut Creek; Santa Inez; Santa Monica; Death
Valley (Cooper).
Subgenus Lunatia Gray.
Shell usually somber colored; covered with a dark, thin epidermis; not so thick as the
typical group; umbilicus open, without funiculum. Operculum corneous.
Type, Natica ampullaria Lam.
355. Polynices (Lunatia) lewisii Gould.
Plate X, Fig. 14.
Natica lewisii Gld., Proc. Bost. Soc. Nat. Hist., 1847, p. 239; Wilkes' Expl. Exped., p. 211,
PI. XV, p. 253, 1852.
Lunatia lewisii Gld., Cpr., Brit. Assn. Rept., 1863, p. 661. Gabb, Pal. Cal., Vol. II, p. 77, 1869.
^= N. reinia^ia Dunker (young), = N. algida Gld. (^fide Tryon, Man. Conch.,
Vol. VIII, p. 35, PI. XIII, figs. II, 12; PI. IX. fig. 70, 1886). Cooper, 7th Ann. Rept.
Cal. St. Min., 1888, p. 247. Keep, West Coast Shells, p. 45, fig. 25, 1892. Dall,
Trans. Wagner Inst. Sci., Vol. Ill, Part II, 1892, p. 374.
Natica (Lunatia) /ifwwzz Gld., Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 211.
The adult may be distinguished from Neverita recluziana by its large size,
open umbilicus, generally more elevated spire, and a shallow, spiral groove near the
316 CALIFOKNIA ACADEMY OF SCIENCES.
anterior portion of the body-wliorl. The upper whorls are more convex and more
distinctly separated from each other by the suture than are the upper whorls of the
latter species. All the specimens found were larger than the average N. recluziana,
some of them being over 100 mm. in altitude.
Rare in the upper San Pedro series of San Pedro, Los Cerritos, Long Beach,
Crawfish George's, and Deadman Island. The specimen figured is from the upper
San Pedro series at San Pedro, and is now in the collection of Delos Arnold.
Living. — Straits of Fuca to San Diego (Cooper): Japan (Tryon): Catalina
Island (Arnold).
Pleistocene. — Santa Barbara; San Nicolas Island (Cooper) : San Pedro (Arnold).
Pliocene. — Kirker's Pass; Santa Barbara; San Fernando (Cooper): Soquel,
Santa Cruz County (Arnold).
Genus Sigaretus Lamarck.
Shell ear-shaped, with minute spire and very large aperture; externally with revolving striae;
color usually white, with sometimes a thin, corneous epidermis. Operculum minute, horny,
subspiral.
Sigaretus neritoideus Linn, is a characteristic species.
356. Sigaretus debilis Gould.
Sigaretus debilis Gld., Jour. Bost. Soc. Nat. Hist., Vol. VI, 1853, p. 379, PI. XIV, fig. 17. Cpr.,
Proc. Zool. Soc, 1856, p. 207. Tryon, Man. Conch., Vol. VIII, p. 57, PI. XXIV,
fig. 65, 1886. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 264. Keep, West Coast
Shells, p. 47, 1892.
"Shell small, much depressed, thin, almost pellucid; whorls two, spire almost coincident
with the general surface; apex at one-fourth the diameter of the shell; periphery obtuse-angular,
becoming more so as it approaches the aperture; ventral surface excavated at the umbilical region,
with a slight unappressed lamina at that point; margin of the aperture having a very slight advance
in the outline, as it approaches the peripheral angle; surface with very numerous and very delicate
obtusely excavated revolving striae, much finer on the ventral than on the dorsal surface."
Dimensions. — Length about 22 mm.
The above is Gould's original description.
Rare in the upjier San Pedro series; one imperfect specimen from that hori-
zon at Los Cerritos, and one nearly perfect one from the lumber yard, San Pedro.
Living. — Monterey to Lower California (Cooper).
Pleistocene.- — San Pedro (Arnold).
Pliocene. — San Diego well (Cooper).
ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 317
Family LXXIX. LAMELLARIID^.
Genus Lamellaria Montagu.
Shell ear-shaped; thin, pellucid, fragile; spire very small; aperture large, patulous; inner
lip receding.
Lamellaria perspicua is a characteristic species.
357. Lamellaria stearnsii Dall.
Lamellaria stearnsii Dall, Am. Jour. Conch., Vol. VII, 1872, p. 122, PI. XV, fig. 6. Tryon,
Man. Conch., Vol. VIII, p. 63, PI. XXVII, figs. 12 and 13, 1886. Keep, West Coast
Shells, p. 47, fig. 27, 1892. Dall, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 211.
Lamellaria depressa Dall, mss., 1866 (^fide Dall).
Shell suborbicular, depressed; spire hardly elevated above last whorl; whorls three, convex;
columella sharp, thin, widely arcuate, loosely twisted, so that the apex is discernible from below;
suture distinct; aperture very effuse, rounded; marked by lines of growth, crossed by microscopic
fine revolving striie.
Dimensions. — Long. 15.2 mm.; lat. il mm.; alt. 7 mm.
Somewhat resembles Sigaretus debilis, but smaller, smoother, and more inflated.
Rare in lower San Pedro series of Deadraan Island; one specimen. Found
also in the Pleistocene at Twenty-sixth Street, San Diego.
Living. — Monterey (Dall): San Pedro (Williamson): West Coast (Keep).
Pleistocene. — San Pedro; San Diego (Arnold).
Superfamily DOCOGLOSSA.
Family LXXX. ACM^IDiE.
Genus Acmgea Eschscholtz.
Shell solid, patuliform; apex erect or anteriorly inclined.
Acmcea mitra Esch. is a characteristic species.
358. Acmsea depicta Hinds.
Patelloida depicta Hds., Ann. Nat. Hist., Vol. X, 1842, p. 82; Voyage Sulphur, p. 53, No. 217, 1844.
Nacella depicta Hds., Proc. Zool. Soc, 1856, p. 204. Cpr. , Brit. Assn. Rept. , 1863, p. 650. Keep,
West Coast Shells, p. 103, 1892.
Shell small, conical, with elongate-elliptical base; apex inconspicuous, about one-fifth length
from posterior extremity; surface ornamented by radiating narrow bands of color.
Dt?nensions. — Long. 7 mm.; lat. 2.8 mm.; alt. 1.8 mm.
This species is close to A. paleacea, but is slightly broader, more depressed,
and has bands of brown radiating from the apex.
One specimen from the upper San Pedro series at Crawfish George's.
Living. — San Diego (Carpenter).
Pleistocene. — San Pedro (Arnold).
318 CALIFORNIA ACADEMY OF SCIENCES.
359. Acmaea insessa Hinds.
Patella insessa Hds., Ann. cS: Mag. Nat. Hist., Vol. X, i860, p. 82, PI. VI, fig. 3.
Nacella incessa Hds., Cpr., Brit. Assn. Rept., 1863, p. 650. Gabb, Pal. Cal., Vol. H, p. 87, 1869.
Cooper, 7th Ann. Rept. Cal. St. Min., 1S88, p. 227. Keep, West Coast Shells, p. 103,
fig. 91, 1892.
Acmaa i?isessa Hds., Dale, Am. Jour. Conch., Vol. VI, 187 1, p. 244, PI. XIV, fig. 3. Trvon,
Man. Conch., Vol. XIII, p. 18, PI. VI, figs. 36, 37, 1891. Williamson, Proc. U. S.
Nat. Mus., Vol. XV, 1892, p. 197.
Shell limpet-shaped, rather thick, brown; apex acute and dark, with light band around dark
spot (this coloration due to the wearing of shell through outer layer); sculpture consists of fine incre-
mental striae; margin inclined to be compressed as the shell grows old; apex slightly anterior.
Dimensions. — Long. 17 mm.; lat. 10 mm.; alt. 11 mm.
Found in the Pliocene of Deadman Island; the lower San Pedro series of
Deadman Island and San Pedro; and the uj^per San Pedro series of Deadman
Island, San Pedro, Los Cerritos, and Crawfish George's. Found in the Pleistocene
at bath-house, Santa Barbara; and at Spanish Bight, San Diego.
Living. — Sitka to San Diego (Dall).
Pleistocene. — San Diego (Cooper): San Pedro; Santa Barbara; San Diego
(Arnold).
Pliocene. — San Pedro (Arnold).
360. Acmaea instabilis Gould.
Patella instabilis Gld., Proc. Bost. Soc. Nat. Hist., Vol. II, 1846, p. 150.
Nacella instabilis Geo., Cpr., Brit. Assn. Rept., 1863, p. 650. Keep, West Coast Shells, p. 103,
1892.
Acmesa itistabilis Gld., Dall, Am. Jour. Conch., Vol. VI, 1871, p. 245. Tryon, Man. Conch.,
Vol. XIII, p. 18, PL VI, figs. 32, 33, 1891. Cooper, Bull. No. 4, Cal. St. Min. Bureau,
Part III, 1894, p. 24.
Shell resembles A. itisessa, but is much larger when adult; apex rounded; sculpture con-
sists of concentric grooves and striee.
Dimensions. — Long. 26.5 mm.; lat. 15 mm.; alt. 12 mm.
Distinguishable from A. insessa by its rounded apex, shallowness, and larger size.
One specimen from upper San Pedro series of Crawfish George's.
Living. — Sitka to Monterey (Dall).
Pleistocene. — San Pedro (Arnold): San Nicolas Island (Bowers).
361. Acmaea mitra Eschscholts.
AcmcBa mitra Esch., Zool. Atlas, Vol. V, p. 18, No. i, PI. XXIII, fig. 4, 1833. Dale, Am. Jour.
Conch., Vol. VI, 1871, p. 241, PI. XIV, fig. i. Cooper, 7th Ann. Rept. Cal. St. Min.,
1888, p. 228. Tryon, Man. Conch., Vol. XIII, p. 24, PI. Ill, fig. 50, 1891. Keep,
West Coast Shells, p. 99, fig. 85, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV,
1892, p. 197.
Scurriamitra Esch., Cpr., Brit. Assn. Rept., 1863, p. 650. Gabb, Pal.jCal., Vol. 11, p. 87, 1869.
ARNOLD — THE PALEONTOLOGY AND STKATIGKAPHY OF SAN PEDRO. 319
Shell conical, apex erect, nearly central, rather sharp, smooth; posterior surface straight;
anterior slightly convex; ornamentation of fine incremental lines, giving- quite a rough surface to
some specimens; aperture oval to nearly circular; rim smooth.
Dinie7isions. — Long. 31 mm.; lat. 27.5 mm.; alt. 19 mm.
Easily distinguishable by its elevated, nearly central apex, comparatively
smooth, light colored surface, and its size.
Not uncommon in the upper San Pedro series of Crawfish George's.
Living. — Sitka to San Diego (Cooper) : Half Moon Bay, San Mateo County
(Arnold).
Pleistocene. — Santa Barbara to San Diego (Cooper): San Pedro (Arnold).
362. Acmasa paleacea Gould.
Acmcea paleacea Gld., Bost. Jour. Nat. Hist., Vol. VI, 1853, P- 376. PL XIV, fig. 5; Mex. and Cal.
Shells, p. 3, PI. XIV, fig. 5, 1853. Dall, Am. Jour. Conch., Vol. VI, 1871, p. 253.
Tryon, Man. Conch., Vol. XIII, p. 20, PI. VI, fig. 42, 1891. Williamson, Proc. U. S.
Nat. Mus., Vol. XV, 1892, p. 197.
Nacella paleacea Gld., Cpr., Brit. Assn. Rept., 1863, p. 650. Keep, West Coast Shells, p. 104, 1892.
"Shell minute, delicate, thin, elongated, laterally compressed, so that the two sides are
parallel; dorsal aspect a long, narrow oval; lateral aspect low, triangular; apex at about the anterior
third, acute, antrorse; surface with delicate lines of growth and a few obtuse radiating ridges along
the dorsal slope at each end; color cinnamon brown. ' '
Dimensions. — Long. 7 mm.; lat. 1.5 mm.; alt. 2 mm.
This shell has little resemblance to any of the others of its genus found in this
formation, and may readily be distinguished by its small size and peculiar shape.
Dr. Dall identified the specimen.
Rare in the upper San Pedro series of Crawfish George's; two specimens found.
Living. — Santa Barbara (Jewett): Monterey; San Diego (Dall).
Pleistocene. — San Pedro (Arnold).
363. Acmfea pelta EschschoUz.
Acmcza pelta EscH., Zool. Atl. , Vol. V, p. 19, No. 5, 1833. Cpr., Brit. Assn. Rept., 1863, p. 650.
Gabb, Pal. Cal, Vol. II, p. 52, 1869. Dall, Am. Jour. Conch., Vol. VI, 1871,
p. 246, PI. XIV, fig. 6. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 228. Tryon,
Man. Conch., Vol. XIII, p. 17, PI. VIII, figs. 86-95, 1891. Keep, West Coast Shells,
p. 102, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 197.
Shell depressed, rounded, with few prominent bulging ribs, which are not developed in the
young shell; apex smooth, obtuse, and anterior to center.
Two specimens sent to Dr. Dall were identified by him as the young of
this species.
Bare in the lower San Pedro series of Deadman Island; and ui^per San Pedro
series of Los Cerritos and San Pedro. Found in the Pleistocene at Pacific Beach,
San Diego; and at Barlow's ranch, Ventura.
320 CALIFORNIA ACADEMY OF SCIENCES.
Living. — Sitka to San Diego (Cooper).
Pleistocene. — Santa Barbara (Cooper): San Pedro; Ventura; San Diego
(Arnold).
364. Acmasa spectrum {Nuttall) Reeve.
Acfneea spectrum Nutt. , Rve., Cpr., Brit. Assn. Rept., 1863, p. 650.
AcmcEa spectrum Nutt., Gabb, Pal. Cal., Vol. II, p. 86, 1869. Cooper, 7th Ann. Rept. Cal. St.
Min., 1888, p. 228. Keep, West Coast Shells, p. 100, figs. 86, 87, 1892. Williamson,
Proc. U. S. Nat. Mus., Vol. XV. 1892, p. 197.
Acmcea spectrtun RvE., Dall, Am. Jour. Conch., Vol. VI, 187 1, p. 251, PI. XIV, fig. 10. Tryon,
Man. Conch., Vol. XIII, p. 14, PI. I, figs. 7-9, 1891.
Shell depressed, with rather acute apex, which is about one-third length of shell fi-om the
anterior margin; ribs very prominent and rugose, generally alternating large and small.
Dimensions. — Long. 26 mm.; lat. 19 mm.; alt. 10 mm.
The commonest of the Acmsedte, and easily distinguishable by the prominent,
rugose ribs.
Rare in the lower San Pedro series of Dead man Island; and rather common
in the upper San Pedro series of Deadman Island and San Pedro.
Living. — Bodega Bay to Lower California (Dall).
Pleistocene. — Santa Barbara; San Pedro (Cooper): San Pedro (Arnold).
Family LXXXI. LIOTIID^.
Genus Delphinoidea Brown.
Shell orbicular, depressed, widely umbilicated; spire short; whorls transversely striated or
cancellated; aperture round, not nacreous; peristome continuous, simple.
Delphinoidea cancellata Marryat is a characteristic species.
[S. D.] Delphinoidea coronadoensis, sp. nov.
Shell minute, orbicular, depressed, milk-white, rather thick for size of shell; spire flattened
beneath plane of upper periphery of the body-whorl; whorls two and one-half, nearly circular in
cross-section; surface ornamented by numerous subequal, rounded spiral ridges, and very minute
transverse lines, the whole giving the surface a cancellated appearance; irregular lines denoting
interruption in growth are common on the body-whorl; suture deeply appressed; umbilicus wide,
deep; aperture suboval; peristome continuous, rather thick, slightly effuse.
Ditnensions . — Maximum diam. 2 mm.; alt. 0.9 mm.
This specie.s, which is the smallest gastropod found in the Spanish Bight
Pleistocene, is named for the Coronado peninsula, into which Spanish Bight extends.
Pleistocene. — San Diego (Arnold).
ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OP SAN PEDRO. 321
Family LXXXII. PHASIANELLID^.
Genus Phasianella Lamarck.
Shell elongated, polished, richly colored; whorls convex; aperture oval, not pearly; inner lip
callous; outer lip thin; opercuhini slielly; callous outside, subspiral inside.
Phasianella fulimoides Lam. is a characteristic species.
365. Phasianella compta Gvtdd.
Phasianella compta Gld., Pac. R. R. Kept., Vol. VI, p. 333, Pi. XI, figs. 25, 26, 1857. Cpr., Brit.
Assn. Rept., 1863, p. 651. Gabb, Pal. Cal, Vol. II, p. 82, 1869. Tryon, Man. Conch.,
Vol. X, p. 173, PL XXXIX, figs. 69-72, 1888. Cooper, 7th Ann. Rept. Cal. St.
Min., 1SS8, p. 25S. Keep, West Coast Shells, p. 89, fig. 74, 1892. Williamson,
Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 199.
Shell small, thin; spire elevated; apex subacute; whorls four, evenly convex; ornamenta-
tion consists of eight obsolete spiral ridges crossed by numerous fine oblique, incremental lines;
suture depressed, distinct; aperture ovate; outer lip thin; inner lip sharp and effuse, with incrustation
extending to umbilical region; a narrow umbilical chink is sometimes present.
Dimensions. — Long. 9.5 mm.; lat. 6 mm. ; body-whorl 7 mm.; aperture 4.2 mm. x 2.8 mm.;
defl. 45 degrees.
Distinguishable from tlie genus Lacuna by lack of distinct umbilical chink,
and by the spiral lines. These lines are slightly oblique and slope anteriorly from
the top of the whorl. The Pleistocene shells often retain their coloration of zigzag,
irregular, transverse, purple lines.
This species is common in the upper San Pedro series of San Pedro; and in
tlie lower San Pedro series at San Pedro and Deadman Island. Found also in the
Pleistocene at Twenty-sixth Street, San Diego.
Living. — San Pedro to Mazatlau (Cooper).
Pleistocene. — San Pedro; San Diego (Cooper; Arnold).
Family LXXXIII. TURBINID^.
Genus Pachypoma Gray.
Shell trochiform, conical, with moderately elevated spire; base concave, not umbilicated;
whorls flattened, rugose, spinously fringed. Operculum oval, subquadrangular, externally convex.
Pachypoma cmlata Chem. is a characteristic species.
366. Pachypoma inaequale Marty n.
Trochus incEqualis Mart., Univ. Conch., Lond., 17S4.
Pachypoma inaqiiale Mart., Dall, Proc. U. S. Nat. Mus., Vol. XV, 1S92, p. 199, PL XXIII,
figs. I, 3. 5-
Trochus gibberosus Chem., Conch. Cab., X, p. 278, vign. 23, 1795.
Pachypotna gibberosum Chem., Cpr., Brit. Assn. Rept., 1863, p. 651. Gabb, Pal. Cal., Vol. II,
p. 83, 1869. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 256. Keep, West Coast
Shells, p. 87, 1892.
Asiralium incequale Mart., Tryon, Man. Conch., Vol. X, p. 244, PL LVIl, figs. 51, 52, 1888.
May 4, 190J.
(41 )
322 CALIFORNIA ACADEMY OF SCIENCES.
Shell of moderate size, conical; spire elevated, subacute; whorls five or six, flat, with numer-
ous oblique, rounded, irregular, transverse ridges, with smaller ridges intercalated on lower part of
whorls; suture impressed, wavy, distinct; aperture subovate; umbilicus obsolete; base flat, ornamented
with several prominent, rounded, rugose spiral ridges with squamose lirulae between.
Dimensions. — Alt. 23 mm.; lat. 25 mm.; defl. 65 mm.
Tliis species resembles Pomnulax undosus quite closely, but may be distinguished
from that sjiecies by lack of prominent keel on anterior margni of whorl, intercalated
transverse ridges, and prominent spiral ridges on base.
Rare in upper San Pedro series of San Pedro.
Living. — Straits of Fuca to Catalina Island (Cooper).
Pleistocene. — Santa Barbara; San Pedro (Cooper): San Pedro (Williamson;
Arnold).
Genus Pomaulax Gnry.
Shell trochiform, elevated, conic, angulated and nodose at the periphery; obliquely ribbed;
not umbilicated; inner lip arcuated with a wide callus, which is channeled, anteriorly truncated.
Type, Pomaulax undosus Wood.
367. Pomaulax undosus Wood.
Trochus undosus Wood, Inde.x, Test. Suppl., PI. LI, fig. i, 182S; Suppl., p. 16, PL V, fig, i, 1859.
Pomaulax undosus Wood, Cpr., Brit. Assn. Rept. , 1863, p. 651. Gabb, Pal. Cal., Vol. II, p. 83,
1869. Tryon, Man. Conch., Vol. X, p. 243, PI. LVIII, figs. 69, 70, 1SS8; Syst. and
Struct. Conch., Vol. II, p. 308, PI. LXXX, fig. 33, 1883. Cooper, 7th Ann. Rept. Cal.
St. Min., 1888, p. 260. Keep, West Coast Shells, p. 89, fig. 75, 1S92. Williamson,
Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 199.
Shell large, conical; spire elevated, subacute; whorls six or seven, flat with undulating,
nodose keel on anterior margin; transverse ridges on upper part of whorl, with small nodes near
middle of shell and toward anterior margin; suture appressed, distinct and wavy; keel prominent on
body-whorl; base flat, with faint spiral sculpture; aperture subovate; columellar protuberance on
some specimens.
Dimensions. — Alt. 40 mm.; lat. 45 mm.; defl. 70 degrees.
This species is characterized by the prominent nodose keel on anterior margin
of whorl. Although the living specimens are common, the fossils are rare in this
locality.
Upper San Pedro series of San Pedro and Crawfish George's. Found also in
the Pleistocene at Pacific Beach, San Diego.
Livivg. — Santa Barbara to Cape St. Lucas; Monterey ? (Cooper).
Pleistocene. — Santa Barbara to San Diego (Cooper): San Pedro; San Diego
(Arnold).
Genus Leptothyra Carpenter.
Shell small, turbinated, thick; not umbilicated; aperture circular, slightly angulated
anteriorly.
Ty|)c, Lep!(ifJii/rn cnrpcntcri Carpenter.
ARNOLD — THE PALEONTOLOGY AND STRATIORAPHV OF SAN PEDRO. 323
368. Leptothyra bacula Carpenter.
Leptonyx bacula Cpr., Brit. Assn. Rcpt., 1863, p. 652. Keep, We^t Coast Shells, p. 87, 1892.
Leptothyra bacula CpR., Gabb, Pal. Cal, Vol. II, p. 85, 1869. Cooper, 7th Ann. Rept. Cal. St.
Min., 1888, p. 245. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892. p. 199
Shell small, turreted, thick; surface sculptured by fine spiral lines; no umbilicus; aperture
circular, slightly angulated anteriorly.
Dimensions. — Alt. 2 mm.; lat. 2.5 mm.
The specimen from the Pleistocene shows the original pink color of the living
shell, and looks very much like a very small Horrisia norrisii, except that the Lep-
tothyra has no umhilicus.
Distinguishable from L. carpenferi and L. paucicostata by its much finer spiral
sculpture and pinkish color.
One specimen from the lower San Pedro series of Deadman Island; also
found in the lower San Pedro series at Los Cerritos. Found in the Pleistocene at
bath-house, Santa Barbara.
Living. — Monterey to Catalina Island (Cooper).
Pleistocene. — Santa Barbara to San Pedro (Cooper) : San Pedro; Santa Bar-
bara (Arnold).
369. Leptothyra carpenteri Pilsbry.
Leptothyra carpenteri Pilsbry, Tryon, Man. Conch., Vol. X, p. 247, PI. XXXIX a, figs. 26-29,
18SS; Nautilus, July, 1890. Williamson, Proc. U, S. Nat. Mus., Vol. XV, 1892, p. 199.
Leptothyra sanguineus Linn., Cpr., Brit. Assn. Rept., 1863, p. 652.
Leptothyra sangiiinea Cpr., Gabb, Pal. Cal., Vol. II, p. 85. 1869. Tryon, Syst. Conch., Vol. I,
PI. II, p. 312, 1882. Cooper, 7th Ann. Rept. Cal. St. Min., p. 245, 188S. (Not
Leptothyra sanguineus LiNN., Syst. Nat., 1760.)
Lrptonyx sangui)iea LiNN. , Keep, West Coast Shells, p. 87, fig. 73, 1892.
Shell small, subconical, thick; spire only slightly elevated; whorls three to four, slightly
convex; body-whorl subangulate anteriorly; whorls ornamented by nine to ten fine, spiral ridges;
aperture circular; not umbilicated; tubercle on lower portion of outer lip; suture slightly im-
pressed, distinct.
Dimensions. — Alt. 8 mm.; lat. lomm. ; defl. 100 degrees.
Distinguishable from L. paucicostata by larger size, greater number and less
prominence of spiral ridges, and by less prominence of suture; distinguishable from
L. bacula by less number and greater j^i'ominence of sjiiral ridges.
Found in lower San Pedro series at Deadman Island, and San Pedro; and
in the ujij^er San Pedro series at San Pedro and Crawfish George's.
Living. — Straits of Fuca to San Diego; Japan (Cooper).
Pleistocene. — Santa Barbara (Cooper): San Pedro (Arnold).
370. Leptothyra paucicostata Dull.
Leptothyra paucicostata Dall, Am. Jour. Conch., Vol. VII, 1872, p. 131, PL XV, fig. 10. Tryon,
Man. Conch., Vol. X, p. 248, PI. LXIII, fig. 27, 18S8. Cooper, 7th Ann. Rept. Cal.
St. Min., 1888, p. 245.
324 CALIFORNIA ACADEMY OF SCIENCES.
Shell smaller than L. carpenleri; whorls ornamented with very prominent, coarse spiral
ridges; a typical specimen showing six on the body- whorl and two small ones in umbilical region;
suture deeply impressed, distinct; aperture circular; lip thick, with tubercle on lower part.
Dimensions. — Alt. 4 mm.; lat. 5 mm.; defi. 100 degrees.
Distinguishable from L. carpenteri and L. bacula by the coarse spiral ribs and
deep suture.
Two specimens found in the lower San Pedro series of San Pedro. Found in
the Pleistocene at the bath-house, Santa Barbara.
Living. — ^Santa Cruz to Monterey (Cooper).
Pleistocene. — Santa Barbara (Cooper): San Pedro; Santa Barbara (Arnold).
Family LXXXIV. TROCHID/E.
Genus Chlorostoma Sv^dinfton.
Shell conoidal, profoundly umbilicated, or umbilical region covered by a callosity: whorls
smooth or subcarinated, the last subangulated at the base; coJumeliar lip spirally twisted around the
umbilicus; outer lip angulated at the base.
Chlorostoma argyrostroma Cheran. i.s a characteristic species.
371. Chlorostoma aureotinctum Forbefs.
Trochus Mireotinclus Fbs., Proc. Zool. Soc, 1850, p. 271. Fischer, Coq. Viv., Turbo, p. 94,
PI. XXXI, fig. I.
Chlorostoma aureotinctum Fbs., Cpr., Brit. Assn. Rept., 1S63, p. 652. Coopek, 7th Ann. Rtpt.
Cal. St. Min., 1888, p. 234. Trvon, Man. Conch., Vol. XI, p. 172, PI. XXVII,
figs. 31-33, 1889. Keep, West Coast Shells, p. 84, 1892. Williamson, Proc. U. S.
Nat. Mus., Vol. XV, 1892, p. 200.
Shell conoidal, spire somewhat elevated; apex obtuse; whorls four, slightly convex; body-
whorl subangular at base; surface roughened by prominent, rounded, irregular, transverse ridges,
which appress against the antecedent whorls and become obsolete at the angles of the whorl; lower
portion of whorl smooth, as is the whole surface of the two posterior whorls; suture distinct; base of
body-whorl furrowed with four grooves which show transverse incremental lirulae at their bottoms;
umbilicus deep and effuse, with bright, yellow stain in the living shell; aperture circular; columellar
lip slightly twisted around umbilicus; outer lip with two small tubercles on inner side of base.
Dimensions. — Alt. 10 mm.; lat. 17.5 mm.; defl. 100 degrees.
Rare in upper San Pedro series of San Pedro.
Living. — Santa Barbara to Lower California (Cooper).
Pleistocene. — Santa Barbara (Cooper): San Pedro (Arnold).
372. Chlorostoma brunneum PhiUppi.
Trochus brunneus Phil., Zeits. Monog. Troch., p. 300, PI. XLIII, fig. 19, 1848. Lischke, Jap.
Meers. Conchyl., p. 99. Fischer, Coq. Viv., p. 365, PI. CXIl, fig. i.
Chlorostoma brumieum Phil., Cpr., Brit. Assn. Rept., 1863, p. 652. Gabb, Pal. Cal., Vol. II, p. 84,
1869. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 234. Tryon, Man. Conch.,
Vol. XI, p. 170, PI. XXVII, figs. 36-38, 1889. Keep, West Coast Shells, p. 83,
fig. 69, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 200, PI. XXI, fig. 8.
AENOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 325
Shell conoidal, thick; whorls six, slightly convex; slight shoulder posteriorly near suture;
ornamentation consists of numerous prominent, fine, oblique, incremental lines; suture impressed,
distinct; umbilicus obsolete; base flat; obsolete spiral ornamentation; outer lip thin, effuse.
DimensioHS. — Long. 28 mm.; lat. 28 mm.; defl. 65 degrees.
Distinguishable from C. montereyi, which il resembles in shape, by more
convex whorls, obsolete umbilicus and lack of spiral ornamentation.
This species is rare in the Pliocene of Deadman Island, and in the upper
San Pedro series of Deadman Island and Crawfish George's.
Living. — Cape Mendocino to San Diego (Cooper): Japan ? (Tryon).
Fleistocp.ne. — Santa Barbara Island (Cooper): San Pedro (Arnold).
Pliocene. — San Pedro (Arnold).
373. Chlorostoma funebrale A. Adams.
Chlorosto7na fimebrale A. Ad., Proc. Zool. Soc, 1854, p. 316. Cpr., Brit. Assn. Rept., 1863, p. 652.
Gabb, Pal. Cal, Vol. II, p. 84, 1869. Cooper, 7th Ann. Rept. Cal. St. Min., 1888,
p. 234. Tryon, Man. Conch., Vol. XI, p. 170, PI. XXVIII, figs. 42-44, 1889. Keep,
West Coast Shells, p. 84, fig. 71, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV,
1892, p. 200, PI. XXI, fig. 7.
Trochus funebralis A. Ad., Fischer, Coq. Viv., p. 173, PI. LVII, fig. 3.
Shell conoidal, thick, black; whorls five, only slightly convex; ornamentation of eight spiral
ridges crossed by fine, oblique liruke of growth; suture di.stinct; base flat; ornamentation same as
whorls, with the oblique incremental lines brought into prominence, as a rule; umbilicus obsolete;
outer lip effuse, with one prominent and one smaller tubercle near umbilical region; inner lip
incrusted.
Dimensions. — Long. iS mm.; lat. 19 mm.; defl. 74 degrees.
Distinguishable by black color, spiral ridges and obsolete umbilicus.
Rare in the lower San Pedro series of Deadman Island and San Pedro; and
in upper San Pedro series of Deadman Island, San Pedro, Los Cerritos, Long Beach,
and Crawfish George's. Found also in the Pleistocene at Barlow's ranch, Ventura;
and at Pacific Beach, San Diego.
Living. — Sitka to San Diego (Cooper).
Pleistocene. — Santa Barbara to San Diego (Cooper): San Pedro; Ventura;
San Diego (Arnold).
374. Chlorostoma funebrale A. Adavis, var. subapertum Carpenter.
Chlorostoma funebrale var. subaperiiim Cpr., Brit. Assn. Rept., 1863, p. 652. Dall, Proc. U. S.
Nat. Mus., Vol. XV, 1892, p. 200, PI. XXI, fig. 6.
Shell resembles G. funebrale, but differs in having more prominent spiral
ridges, which are usually much more rugose, and in having a prominent umbilical pit.
Found in same localities as C. funebrale.
Living. — Vancouver district (Carpenter) : West Coast.
Pleistocene. — San Pedro (Arnold).
326 CALIFORNIA ACADEMY OF SCIENCES.
375. Chlorostoma gallina Fvrbcf!.
Trochis ( Monodonla) g^allijia Fbs., Pioc. Zool. Soc, 1S50, p. 271, PI. XI, fig. 8.
Trochus gallina Fbs., Fischer, Coq. Viv., p. 258, PI. CXI, fig. i.
Chlorosloma gallina Forbes, Cpr., Brit Assn. Rept., 1863, p. 652. Tryon, Man. Conch., Vol. XI,
p. 169, PI. XX, fig. 15; PI. XXVIII, figs. 52 and 53, 1889. Keep, West Coast Shells,
p. 84, fig. 70, 1892. Williamson, Proc. U. S. Nat. Mus.,Vol. XV, 1892, p. 200.
Shell conoidal, thick; whorls five, flat, slightly shouldered posteriorly near suture in some
specimens; ornamentation consists of numerous obsolete spiral ridges, and irregular, oblique, trans-
verse ridges of varying prominence; suture distinct; umbilicus nearly obsolete; base flat, same orna-
mentation as whorls; outer lip effuse, with prominent tubercle near umbilicus.
Dimensions. — Long. 20 mm.; lat. 21 mm.; defl. 80 degrees.
Mcst specimens show olilique, alternating dark and liglit, irregnlar lines,
which characterize the living shells.
Rare in upper San Pedro series of San Pedro, Crawfish George's, and Dead-
man Island. Found in the Pleistocene at Pacific Beach, San Diego.
Living. — Santa Barbara Islands to Lower California (Carpenter).
Pleistocene. — San Pedro; San Diego (Arnold).
376. Chlorostoma montereyi Kiener.
Platk X, Fro. 19.
Trochus montereyi Kiener, Species Trochus, PI. XXXIII, figs, i and la. Fischer, Coq. Viv.,
p. 104, Pi. XXXIil, fig. I. Tryon, Man. Conch., Vol. XI, p. 171, PI. XXVII,
figs. 27, 28, 29, 1889.
Omphalius pfeifferi Vuii^., Cpr., Proc. Zool. Soc, 1856, p. 200.
Chlorostoma pfeifferi Phil., Cpr., Brit. Assn. Rept., 1863, p. 652. Gabb, Pal. Cal., Vol. II, p. 84,
1869. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 234. Keep, West Coast
Shells, p. 83, 1892.
Chlorostoma montereyensis Kien. , Williamson, Proc. U. S. Nat. Mas., Vol. XV, 1892, p. 200.
Shell conical; whorls seven, flat (on some specimens the whorls have a shoulder on the
posterior part); suture distinct but n(5t impressed; surface of upper five or si.K whorls ornamented
with five flat, spiral ridges, the space between the ridges being crossed by minute incremental lines,
which slope anteriorly at quite an angle; ornamentation on the rest of the whorls indistinct; base
flat, indistinctly ornamented as on the upper whorls; umbilicus open, smooth and slighdy keeled
aperture elliptical.
Dimensioyis. — Alt. 35 mm.; lat. 33 mm.; defl. 65 degrees.
The specimen described was identified by Dr. Dall.
Found in the Pliocene of Deadman Island; in the lower San Pedro series
of Deadman Island; and in the upper San Pedro series of Deadman Island, Crawfish
George's, and San Pedro. Fouiul in the Pleistocene at Pacific Beach, San Diego.
The specimen figured is from the upper San Pedro series at Crawfish George's, and
is now in the collection of Delos Arnold.
Livincj. — Baulinas Bay to San Diego (Cooper).
ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 327
Pleistocene. — Sauta Barbara to San Diego (Cooper) : San Pedro; San Diego
(Arnold).
Pliocene. — San Pedro (Arnold).
Subgenus Omphalius Philipjn.
Shell convex-trochiform, uuibilicated; whorls with revolving series of granules; the last
uhurl bluntly angulated at the periphery; umbilicus encircled by a callosity; columellar lip termi-
nated by a tooth anteriorly, below which are small tubercles; outer lip usually internally grooved.
Clilorodoma viridnlus Gmel. is a characteristic sjjecies.
377. Chlorostoma (Omphalius) viridulum var. ligulatum Menke.
Trochus ligulahis Menke, Zeit. f. Mai., 1850, p. 173. Fischer, Coq. Viv., p. 382, PI. CXV, hg. 5.
Omphalius ligulahis Menke, Cpr., Cat. Mazatlan Shells, p 235.
Omphalius fusccsccns Phil., Cpr., Proc. Zool. Soc, 1S56, p. 224. Cpr., Brit. Assn. Rept., 1S63,
p. 652. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 255. Keep, West Coast
Shells, p. 82, fig. 68, 1892.
Tiockus luridus Nutt., Cpr., mss., Brit. Assn. Rept., 1856, p. 233.
Chlorostoma (^Omphalius) viridulum var. ligulatum Menke, Trvon, Man. Conch., Vol. XI, p. 177,
PI. XXIX, figs. 58-60, 1889. Dall, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 200.
Shell turbinated, thick; whorls five, conve.x to nearly flat; body-whorl subangular at base;
ornamentation consists of seven to eight prominent nodose spiral ridges; suture distinct, sometimes
quite deeply impressed; base flat, with ornamentation same as whorls, except less prominent;
umbilicus deep, effuse, smooth; outer lip eftuse, denticulated on lower portion.
Dimeiisions. — Alt. 17 mm.; lat. 18 mm.; defl. 80 degrees.
Some of the specimens show the mottled coloration of the live shell.
Distinguishable by denticulation and ornamentation.
Rare in lower San Pedro series of Deadman Island and San Pedro; common
in the upper San Pedro series of Los Cerritos and Crawfish George's; but rare in the
upper San Pedro series of Deadman Island and San Pedro.
Livincj. — Catalina Island to San Diego (Cooper): Mazatlan (Carpenter).
Pleistocene. — San Pedro (Cooper; Arnold).
Genus Thalotia Gray.
.Shell ovate-turriculated, rather thick; not umbilicated; whorls flattened, with revolving ribs,
which are sometimes granulated; aperture subrotund; columella tuberculated, truncate in front; outer
lip rather thick, crenulated within.
Thtilotia conicus Gray is a characteristic species.
378. Thalotia caffea Gabb.
Turcica I Ptychstylis) caffea Gabb, Proc. Cal. Acad. Sci., Vol. Ill, 1865, p. 187; Pal. Cal., Vol. II,
pp. 16, 84, PI. Ill, hg. 27, 1869.
Thalotia caffea Gabb, Cooper, Geog. Cat. West Coast Shells, p. 26, 1S67. CooPER, 7th Ann.
Rept. Cal. St. Min., 1888, p. 267.
328 CALIFOKNIA ACADEMY OF SCIENCES.
Shell conical, thin; spire elevated, subacute; whorls five or six, flat; ornamentation consists
of smooth keel on anterior part of whorl and row of nodes on posterior part next to suture; flat space
between these two smooth; both keel and flat surface nodose on anterior part of body-whorl; suture
very deep and narrow; body-whorl acutely angulated at base; base slightly convex, ornamented with
several alternating large and small nodose spiral ridges; aperture trapezoidal; outer lip thin, bulging
below; columella incrusted, and having two plications.
Dimensions. — Alt. 19 mm.; lat. 16 mm.; defl. 70 degrees.
Distinguishable from the CnllinMoma' by tiie deep, narrow suture, large
aperture, with bulging lower [>art of outer lip, and plicated columella.
Found in Pliocene of Deadman Island; one specimen from lower San Pedro
series of Deadman Island.
Living. — Monterey (Cooper): San Pedro (Raymond).
Pleistocene. — Santa Barbara; San Pedro (Cooper): San Pedro (Arnold).
Pliocene. — San Pedro (Arnold).
Genus Phorcus Risso.
Shell conoidal, umbilicated; umbilicus cylindrical or infundibuliform; whorls frequently tuber-
culated above and with channeled suturt-; ct)luiiiella sometimes terminating in a tubercular tooth.
Phoycus magiix Linn, is a characteristic species.
379. Phorcus pulligo Martyn.
Trochus pulligo Mart., Univ. Conch., PL LXXVI, 1784. Philippi, Conch. Cab., p. 84, PI. XV,
fig. 3. Fischer, Coq. Viv., p. 232, PI. LXXX, fig. i.
Phorcus pulligo Makt., Cpr., Brit. Assn. Rept., 1863, p. 653. Cooper, 7th Ann. Rept. Cal. vSl.
Min., 1888, p. 259.
Chlorostoma pulligo Mart., := C. niarcidus Gld. {^fide Tryon, Man. Conch., Vol. XI, p. 171,
PI. XXVI, figs. 23, 24, 25, 1889).
Shell broadly conical; whorls five, flat, but somewhat obsoletely ribbed or bluntly nodose
in most specimens; surface shows extremely oblique lines of growth; suture distinct but not much
impressed; base flat and smooth, except for faint incremental lines; aperture subovate; lips not
thickened; umbilicus smooth, round and effuse.
Dimensioyis. — Alt. 18 mm.; lat. 22 mm.; defl. 78 degrees.
This shell is often confused with Chlorostoma montereyi, but may be distin-
guislied from that species by its gradually expanding umbilicus, greater deflection,
and lack of spiral sculpture. Specimens of this species were identified by Dr. Dall.
Rather common in the upper San Pedro series of Crawfish George's. The
specimen figured is from the upper San Pedro series at Crawfish George's, and is
now in the collection of Delos Arnold.
Living. — Sitka to San Pedro (Cooper.)
Pleistocene. — San Pedro; San Diego (Cooper): San Pedro (Arnold).
ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 329
Genus Calliostoma Suuinson.
Shell trochiform, conical, not unibilicated; last whorl angulated and usually ribbed at the
periphery; aperture quadrangular; columella simple, oblique, often ending in a tooth in front.
Calliostoma zizyphinvm Linn, is a ciiaracteristic species.
380. Calliostoma annulatum Martyn.
Trochus annulatiis Mart., Univ. Conch., Vol. I, fig. 33, 1784. Philippi, Conch. Cab., p. 11,
PL III, figs. 3, 4.
Zizyphiniis annulatus Mart., A. Ads., Proc. Zool. Soc, 1851, p. 164. Gray, Dieffenbach's
N. Zealand, p. 237, No. 72.
Calliostoma annulahmi Mart., Cpr., Brit. Assn. Rept., 1863, p. 652. Gabb, Pal. Cal., Vol. II,
p. 83, 1S69. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 231. Tryon, Man.
Conch., Vol. XI, p. 363, PI. LXVII, fig. 43, 1889. Keep, West Coast Shells, p. 79,
fig. 64, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, PL XXII, fig. 2.
Shell conical; whorls seven, slightly angulated in center, and ornamented with sharply
nodose spiral ridges which increase by intercalation from two on third whorl to seven or eight on
body-whorl; suture deep, distinct; body-whorl acutely angulated at base; base nearly flat, ornamented
with, numerous smooth, rounded spiral lines; aperture subquadrate; columella nearly straight,
thickened.
Dimensions. — Alt. 17 mm.; lat. 16 mm.; defl. 67 degrees.
Distinguishable by slightly angulated whorls, nearly equally prominent nodose
ridges, and nearly straight cohimella.
Quite rare in the upper San Pedro series of San Pedro.
Living. — Straits of Fuca to San Diego (Cooper).
Pleistocene. — San Pedro to San Diego (Cooper): San Pedro (Arnold).
Pliocene. — San Diego well (Dall).
381. Calliostoma canaliculatum Martyn.
Trochus canaliculatus Mart., Univ. Conch., Vol. I, fig. 32, 1784.
Zisyphinus canaliculatus Mart., Gray, Dieffenbach's N. Zealand, p. 327. Reeve, Conch. Icon.,
fig. 18.
Calliostoma canaliculatujn Mart., Cpr., Brit. Assn. Rept., 1863, p. 652. Gabb, Pal. Cal., Vol. II,
p. 83, 1869. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 231. Tryon, Man.
Conch., Vol. X, PL XLI, fig. 34, 1888; VoL XI, p. 361, PL LXVII, fig. 49, 1889.
Keep, West Coast Shells, p. 80, fig. 65, 1892. Williamson, Proc. U. S. Nat. Mus.,
Vol. XV, 1892, PL XXII, fig. 6.
Shell conical; whorls six, flat, ornamented with very prominent rounded, spiral ridges, two
on the third and fourth whorls, and then increasing by intercalation until the body-whorl in some
specimens has five or six prominent ridges, with a less number of auxiliary riblets in between; suture
deeply impressed, forming a canal; aperture subquadrate; base flat, and ornamented in the same way
as the whorls; lip as in C. costatinn.
Dimensions. — Long. 19 mm.; lat. 20 mm.; defl. 67 degrees.
Distinguishable by flat whorls, sutural canal, and few large spiral ridges.
( 42 ) April 29, 1903.
330 CALIFOKNIA ACADEMY OF SCIENCES.
Rare in the Pliocene of Deadman Island, and in the lower San Pedro
series of Deadman Island and San Pedro; common in the upper San Pedro series of
Deadman Island, San Pedro, Los Cerritos, and Crawfish George's. Found in the
Pleistocene at Spanish Bight, and in the Pliocene at Pacific Beach, San Diego.
Living. — Straits of Fuca to San Diego (Cooper).
Pleistocene. — San Pedro to San Diego (Cooper): San Pedro; San Diego
(Arnold).
Pliocene. — San Pedro; San Diego (Arnold).
382. Calliostoma costatum Martyn.
Trochus costatus Mart., Univ. Conch., PI. X, fig. 3, 1784. Philippi, Conch. Cab., p. 275,
PI. XL, fig. 8.
Calliostoma costatum Mart., Cpr., Brit. Assn. Rept., 1863, p. 652. Gabb, Pal. Cal., Vol. II,
p. 83, 1869. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 231. Tryon, Man.
Conch., Vol. XI, p. 362, PI. XVI, figs. 6, 9; PI. XVIII, fig. 16, 1889. Keep, West
Coast Shells, p. 81, fig. 66, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV,
1892, PI. XXII, fig. I.
Zizyphinus filostis Wood, Reeve, Conch. Icon., fig. 27.
Shell turbinated, thick; whorls five, convex, and ornamented with about eight, almost equally
prominent, spiral ridges; fine oblique incremental lines visible on most specimens; suture deeply
impressed; base slightly convex, ornamented same as whorls; outer lip slightly effuse; columella
thickened and incrusted.
Dimensions. — Alt. 22 mm.; hit. 20 mm.; defl. 70 degrees.
Distinguishable by the even convexity of the whorls, numerous, comparatively
smooth, spiral ridges, and thickne.ss of the shell, which is unusual for a member of
this genus.
Rare in the lower San Pedro series of Deadman Island and San Pedro; and
in the upper San Pedro series of Crawfish George's, Los Cerritos, and San Pedro.
Found in the Pleistocene at Pacific Beach, San Diego.
Living. — Sitka to San Diego (Cooper).
Pleistocene. — San Pedro to San Diego (Cooper): San Pedro; San Diego
(Arnold).
Pliocene. — San Fernando, Los Angeles County (Cooper).
383. Calliostoma gemmulatum Carpenter.
Calliostoma gemmulatum Cpr., Brit. Assn. Rept., 1863, p. 653; Proc. Cal. Acad. Sci., \'ol. Ill,
1864, p. 215. Cooper, 7th Ann. Rept. Cal. .St. Min , 1888, p. 231. Trvon, Man.
Conch., Vol. XI, p. 371, PI. LXVII, fig. 54, 1889. Keep, West Coast Shells, p. 81,
1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, PI. XXII, fig. 3.
Spire more acute than in other species of the genus; whorls six to seven, concave above,
convex below; convex part has two or three rows of granular spiral ridges; concave surface orna-
mented with a few fine granular spiral ridges; suture indistinct; base flat, marked by several smooth
spiral ridges; aperture circular.
Dimensions. — Alt. 18 mm.; lat. 15 mm.; defl. 46 degrees.
ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 331
Found in upper San Pedro series of San Pedro, Los Cerritos, and Crawfish
George's. Found in the Pliocene at Packard's Hill, Santa Barbara; and in the
Pleistocene at Spanish Bight, San Diego.
Living. — -San Pedro to San Diego (Cooper).
Pleistocene. — San Pedro to San Diego (Cooper): San Pedro; San Diego,
(Arnold).
Pliocene. — Santa Barbara (Arnold).
384. Calliostoma tricolor Guhh.
Calliostoma tricolor Gabb, Proc. Cal. Acad. Sci., Vol. Ill, 1865, p. 186; Pal. Cal. , Vol. II, p. 17,
PI. Ill, fig. 28, 1869. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 231. Tryon,
Man. Conch., Vol. XI, p. 370, PI. LXVII, fig. 52, 1889. Keep, West Coast Shells,
p. 82, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, PI. XIX, fig. 8.
Shell conical; spire elevated, subacute; whorls five to si.\, flat to concave, with prominent,
rounded keel on anterior margin; surface ornamented with fine spiral lines; suture impressed, dis-
tinct; base nearly flat, ornamented with fine spiral ridges and furrows; aperture subcircular; outer
lip thin; columella slightly incrusted.
Dimensions. — Alt. 11 mm.; lat. 11 mm.; defl. 66 degrees.
Distinguishable by the prominent, smooth keel on the anterior part of
whorls; and by the concavity and inconspicuous ornamentation of the upper part
of the whorls.
Rare in the Pliocene at Deadmau Island; in lower San Pedro series at San
Pedro; and in upjier San Pedro series of Crawfish George's, San Pedro, and Los
Cerritos. Found in the Pleistocene at Spanish Bight, San Diego.
Living. — New Year Point to San Diego (Cooper): San Pedro (Arnold).
Pleistocene. — San Pedro to San Diego (Cooper): San Pedro; San Diego
(Arnold).
Pliocene. — San Pedro (Arnold).
Genus Norrisia Baijle.
Shell thick, conoidal, orbicular, covered by an epidermis, smooth; widely umbilicated, umbili-
cus surrounded by the callous extension of the columella; outer lip not thickened or sculptured within.
Norrisia norrisii Sby. is a characteristic species.
385. Norrisia norrisii Sowerby.
TrocMschics norrisii Sby., Tank. Catalogue, 1825. Cpr. , Brit. Assn. Rept., 1863, p. 652.
= T. convexus Cpr. {^fide Gabb, Pal. Cal., Vol. II, p. 85, 1869). Tryon, Syst. and
Struct. Conch., Vol. II, p. 315, PI. LXXXI, fig. 64, 1883. Cooper, 7th Ann. Rept.
Cal. St. Min., 1888, p. 268. Keep, West Coast Shells, p. 86, fig. 72, 1892.
Norrisia ?iorrisii Sby., Dall, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 200.
Shell of medium size, conoidal, orbicular, thick; spire only slightly elevated above body-
whorl; whorls three or four, only very slightly convex, smooth except for lines of growth; suture
332 CALIFORNIA ACADEMY OF SCIENCES.
only slightly appressed, distinct; aperture subtriangular; outer lip thin, slighdy bowed anteriorly;
umbilicus large, deep, surrounded by callous extension of the columella.
Dimensions. — Alt. 32 mm.; lat. 40 mm.
Described from a living specimen.
Found in upper San Pedro series at Deadman Island. Found also in the
Pleistocene at Pacific Beach, San Diego.
Living. — Santa Barbara to San Diego (Cooper).
Pleistocene. — Santa Barbara (Cooper): San Pedro; San Diego (Arnold).
Genus Margarita Leach.
Shell thin, globular-conical, umbilicated; whorls rounded, smooth; aperture rounded,
pearly; lip sharp, smooth.
Margarita helicina Fabr. is a characteristic species.
386. Margarita optabilis Carpenter, var. knechti, var. nov.
Plate V, Fig. 14.
Gibbida optabilis Cpr., Brit. Assn. Rept., 1863, p. 653.
Shell small, conical, thin; turbinated apical whorls; whorls five; upper whorls rather angular,
slightly tabulated above; body-whorl rounded, slightly angulated at base; two prominent spiral
ridges, one at angle of whorl, the other near anterior margin; between these two ridges is a slightly
concave surface sometimes ornamented with faint spiral ridges; oblique incremental lines quite
prominent; suture impressed and distinct; base of body-whorl only slightly convex, and ornamented
by five spiral ridges; umbilicus large, deep, effuse, smooth; aperture subrotund; inner lip incrusted
and projecting slightly over umbilicus.
Dime7isions . — Alt. 8.5 mm.; lat. 8 mm.; body-whorl 6.5 mm.; aperture 4.5 mm.; defl.
70 degrees.
Some of the specimens retain their mottled coloration. The sculj^ture varies
much in this variety, the number of spiral ridges varying; and the ridges sometimes
being nodose and sometimes smooth.
Sjiecimens pronounced variety of M. optahiVxM by Dr. Dall.
Common in lower and rare in upper San Pedro series of San Pedro. The
specimen figured is the type, which is from the lower San Pedro series at San Pedro,
and is now in the United States National Museum.
Fleistocene. — San Pedro (Arnold).
387. Margarita optabilis Carpenter, var. nodosa, var. nov.
Plate V, Fig. 13.
Gibbula optabilis Cpr., Brit. Assn. Rept., 1863, p. 653.
Shell small, distinctly conical, thin; whorls five, flat, and ornamented by two prominent
slightly nodose spiral ridges, each about one-fourth width of whorl from margin; between these two
ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OP SAN PEDRO. 333
ribs, and also near the posterior margin of whorl, are less prominent ridges; incremental lines visible;
body-whorl angular, with nodose ridge on angle; base of this whorl nearly flat, and ornamented with
two prominent nodose spiral ridges and several lesser ones; umbilicus deep, but not very eflTuse;
aperture ovate; inner lip slightly overlapping umbilicus; suture not impressed, indistinct.
Dimetisiotis, — Alt. 6.5 mm.; lat. 6.5 mm.; body-whorl 5 mm.; aperture 3.5 mm.; defl.
75 degrees.
This variety is distinguishable by its simple conical shape, flat whorls, and
nodose ridges. It may grade into the turbinated, convex-whorled variety, M. knechti,
although no mutations have been found in the large series at hand. This form was
pronounced a variety of M. optabilis by Dr. Dall.
Found in the lower San Pedro series of San Pedro and Deadman Island.
The specimen figured is the type, which is from the lower San Pedro series at San
Pedro, and is now in the United States National Museum.
Pleistocene. — San Pedro (Arnold).
388. Margarita parcipicta Carpenter, var. pedroana, var. nov.
Plate V, Fig. 16.
Gibbula parcipicta CpR., Brit. Assn. Rept., 1863, p. 653; Ann. & Mag. Nat. Hist., 3rd Ser.,
Vol. XIV, 1864, p. 427.
Shell small, thin, globular, conical; spire elevated, subacute; whorls four, rounded, tabulated
near posterior margin; four spiral ridges on upper whorls; suture deeply impressed and distinct;
base of body-whorl rounded, and ornamented by fine spiral ridges; umbilicus deep and effuse;
aperture subcircular.
Dimensions. — Alt. 5.5 mm.; lat. 5.5 mm.; body-whorl 4.5 mm.; aperture 3 mm.; defl.
80 degrees.
Specimens pronounced variety of M. parcipicta by Dr. Dall.
Found in the lower San Pedro series at Deadman Island and San Pedro; and
in the upper San Pedro series at Deadman Island, San Pedro, and Los Cerritos.
The sjjecimen figured is the type, which is from the lower San Pedro series at San
Pedro, and is now in the United States National Museum.
Pleistocene. — San Pedro (Arnold).
389. Margarita pupilla Gould.
Plate X, Fio. 15.
Trocluts pjipilliis Gld , Proc. Bost. Soc. Nat. Hist., Vol. Ill, 1850, p. 91; Wilkes' Expl. E.xped.,
Vol. XII, p. 186, fig. 208, 1852.
Margarita pupilla Gld., = M. calostoma A. Ads. i^fide Cpr., Brit. Assn. Rept., 1S63, p. 653).
=: M. salmonea CpR. {Jide Cooper, 7th Ann. Rept. Cal. St. Min. , 1888, p. 249).
Trvon, Man. Conch., Vol. XI, p. 295, PI. XLIV, figs. 29-32, 1889. Keep, West
Coast Shells, p. 78, fig. 63, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV,
1892, p. 202.
Shell small, ovate-conic, rather solid; whorls five, convex, flattened slightly above, forming
a narrow, tabulate band just below suture; body-whorl obtusely angulated; surface sculptured with
334 CALIFOENIA ACADEMY OF SCIENCES.
small, flattened, subeqiial, equidistant, revolving ribs, five on the upper whorls; interspaces orna-
mented by fine, oblique, incremental lines; base of body-whorl nearly flat, and ornamented with
numerous fine, revolving lines, which become coarser near umbilicus; suture deeply impressed, dis-
tinct; aperture circular; columella somewhat arcuate; umbilicus small, groove-like; outer lip sharp,
nacreous layer on inner lip.
Dimensions. — Alt. 5.8 mm.; lat. 8 mm.; defl. 67 degrees.
Somewhat resembles Solariella peramabilis, but may be distingiiislied by smaller
umbilicus; flatter, finer sculptured base; whorls less flattened above and finer sculp-
tured, both spiral and transverse. Dr. Dall pronounced the Pliocene specimen a
variety of M. 'pupilla.
Found in Pliocene at Deadman Island; two specimens, one of which is figured,
and is now in the collection of Delos Arnold. Found also in the Pleistocene at
the bath-house, Santa Barbara.
Living. — Alaska to Catalina Island, rare at latter place (Cooper).
Pleistocene. — Santa Barbara (Cooper; Arnold).
Pliocene. — San Pedro (Arnold).
Genus Solariella S. Wood.
Shell thin, globular-conical; generally with wide crenated umbilicus; whorls rounded,
sculptured; aperture rounded; lip sharp, smooth.
Solariella peramabilis Cpr. is a characteristic species.
390. Solariella cidaris A. Adams.
Plate VII, Fig. 11.
Margarita cidaris A. Ad., Cpr., Brit. Assn. Rept., 1863, p. 653. Cpr., Ann. Mag. Nat. Hist., 3rd
Sen, Vol. XIV, 1864, p. 426; Vol. XV, 1865, p. 29. Cooper, 7th Ann. Rept. Cal. St.
Min., 1888, p. 249 (young); ^= Solariella oxybasis Dall {fide Cooper, Bull. No. 4, Cal.
St. Min. Bureau, Part 3, 1S94, p. 27).
Turcicula cidaris (A. Ad.) Cpr., Tryon, Man. Conch., Vol. XI, p. 331, 1889.
Solariella cidaris A. Ad., Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 202, Pi. XXII,
fig- 4-
Shell conical; spire elevated, subacute; whorls six to seven; four upper whorls only slightly
conve.x; lower whorls very convex; surface ornamented with spiral rows of nodes which grade into
nodose ribs on the lower side of the body-whorl; suture deeply impressed; aperture circular; outer
lip thin; inner lip and columella enameled, the incrustation completely obscuring the small umbilicus
in most specimens.
Dimensions. — Alt. 40 mm.; lat. 33 mm.; body-whorl 26.5 mm.; aperture 13 mm.; defl.
66 degrees.
The specimen described and figured is an exceptionally large one, the average
altitude being only 18 mm. Identification by Dr. Dall.
Rare in the Pliocene; only about a dozen specimens found, and all of these
from the Pliocene of Deadman Island. According to Dr. Cooper, San Marcial is on
ARNOLD — THE PALEONTOLOGY AND STRATIGKAPHT OF SAN PEDRO. 335
the peninsula of Lower California, and is in the Tertiary belt. This would corres^oond
to the horizon of the formation at Deadman Island, where they are found only in the
Pliocene. The specimen figured is from the Pliocene of Deadman Island, and is now
in the collection of Delos Arnold.
Living. — Neeah Bay to Catalina Island (dredged) (Cooper).
Pleistocene. — San Marcial (Carpenter).
Pliocene. — San Pedro (Arnold; Williamson).
391. Solariella peramabilis Carpenter.
Plate VII, Fio. 2.
Solariella peramabilis CpR., Brit. Assn. Rept., 1863, p. 653. Cooper, 7th Ann. Rept. Cal. St. Min.,
1888, p. 265. Tryon, Man. Conch., Vol. XI, p. 312, PI. LXVII, figs. 59-61, 1889. Will-
iamson, Proc. U. S. Nat. Mus. , Vol. XV, 1892, p. 202.
Shell small, conical; spire elevated, subacute; whorls five, conve.x, with narrow tabulate band
just anterior to suture, and ornamentation of five or six spiral ribs crossed by fine lirulae; suture
deeply impressed; aperture circular; umbilicus open, large, with three internal spiral lines.
Dimensions. — Alt. 14.5 mm.; lat. 12 mm.; body-whorl 10.2 mm.; aperture 5 mm.; defl.
82 degrees.
The specimen described was identified by Dr. Dall.
Rare in the Pliocene; four specimens found in the Pliocene of Deadman
Island. The specimen figured is from the Pliocene of Deadman Island, and is now
in the collection of Delos Arnold.
Living. — Catalina Island (30 fathoms) (Williamson).
Pliocene. — San Pedro (Arnold).
Family LXXXV. CYCLOSTREMATIDiE.
Genus Vitrinella C. B. Adams.
Shell minute, depressed turbiniform; widely umbilicated; aperture large, rounded.
Vitrinella anomala d'Orb. is a characteristic species.
392. Vitrinella williamsoni Ball.
Vitrinella ivilliamsoni Dall, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 202, PL XXI, figs. 2 and 3.
" Shell small, white, depressed, with two and a half whorls; spire flattened; suture appressed,
with a shallow channel or excavation outside of the appressed margin of the whorl, outside of which
the convexity of the whorl rises higher than the suture; base slightly more rounded than the upper
side, with a wide and flaring umbilicus; periphery rounded; aperture rounded, oblique; surface pol-
ished, finely striated here and there by the incremental lines, which are most prominent above.
"Dimensions. — Maximum diameter of shell, 5.5 mm.; minimum diameter, 4.5 mm.; alti-
tude, 1.25 mm."
336 CALIFORNIA. ACADEMY OF SCIENCES.
Several specimens of this species were found in the lower San Pedro series of
San Pedro. They were in a perfect state of preservation, and if they liad been
found on the beach would, no doubt, have been called "dead shells." It is possible
that some of the shells reported as "dead on beach" have been washed down from
the fossil beds, and have been listed as living.
Found in the upper San Pedro series of San Pedro, and the lower San Pedro
series of Deadman Island; rare.
Living. — Sau Pedro (Williamson).
Pleistocene. — San Pedro (Arnold).
Superfamily ZYGOBRANCHI A.
Family LXXXVI. HALIOTIDiE.
Genus Haliotis Linne.
Shell ear-shaped, with a small flat spire; aperture very wide, iridescent; exterior striated,
dull; outer angle perforated by a series of holes, those of the spire progressively closed.
Haliotis gigantea Chemn. is a characteristic species.
393. Haliotis fulgens Philippi.
Haliotis fulg ens Phil., Zeitschr. f Mai., p. 150, 1S45; Abbild. und Beschreib., p. 11, Pis. VII and
VIII, fig. I, 1847. Cpr., Brit. Assn. Rept., 1863, p. 574. Tryon, Man. Conch., Vol.
XII, p. 81, PL XII, figs. 61, 62, 1890. Williamson, Proc. U. S. Nat. Mus., Vol.
XV, 1892, p. 198.
Haliotis splendens RvE., Icon. Conch., PI. Ill, fig. 9. Keep, West Coast Shells, p. 90, fig. 76,
1892. Weinkauff, Conch. Cab., p. 24, Pis. VII and VIII.
Shell large, flat, oval; spire very slightly raised near margin of shell; surface spirally
grooved, the grooves appearing as ridges on the interior; holes four to seven, elevated margins;
interior highly colored; outer layer of shell brownish red.
Dimensions. — Long. 112 mm.; lat. 88 mm.; depth 21 mm.
Distinguished from H. rufescens and H. cracheroidii by grooved surface and
colors of interior.
This specimen, which was found in the conglomerate of the upper San Pedro
series of Deadman Island, is probably the first authentic record of an Haliotis from
the Pleistocene of California. It was a perfect specimen when found, but in remov-
ing it from the matrix it was unfortunately broken into several fragments. A small
but perfect specimen of this species was found in the Pleistocene (upper San Pedro
series) at Spanish Bight, San Diego.
Dr. Cooper has reported //. cracheroidii and H. ri/fescens from the Pleistocene
of San Pedro, but upon examination of the fossils (?) upon which he based his rejwrt,
which are now in the State Museum Collection at the University of California, they
ARNOLD— THE PALEONTOLOGY AND STEATIGEAPHT OP SAN PEDRO. 337
were found to be recent shells from the kitchen-middens that overlie all of the San
Pedro fossil deposits. The mistake of reporting kitchen-midden shells as " Pleisto-
cene " and "Pliocene" has been made by a number of collectors, who have mis-
taken these accumulations for fossil deposits. The two species of Haliotia above
referred to, besides H. fulgens, are common in many of the kitchen-middens along
the coast, and especially so in those around San Pedro.
Living. — Monterey to Lower California (Carpenter).
Pleistocene. — San Pedro; San Diego (Arnold).
Family LXXXVII. FISSUEELLID^.
Subfamily FISSURELLIDEIN^.
Genus Lucapina Gray.
Shell oval-oblong, conic, depressed, cancellated; summit subcentral, the oval opening sur-
rounded by a callus; margin crenulated.
Lucapina crenidata Sby. is a characteristic species.
394. Lucapina crenulata Sowerhy.
Fissurella cremdata Sby., Tank. Catalogue, App., p. vi, 1825; Conch. 111., No. 19, figs. 31, 38, 1831.
Z-i^fiT/J/wa trif?;/^/^/^ Sby., Cpr., Proc. Zool. Soc. , 1856, p. 223. Cpr., Brit. Assn. Rept., 1863, p. 651.
Gabb, Pal. Cal. Vol. II, p. 85, 1869. Tryon, Struct, and Syst. Conch., Vol. II, p. 326,
PI. LXXXIII, fig. 17, 1883. Tryon, Man. Conch., Vol. XII, PI. XLIV, figs. 95, 96,
1890. Keep, West Coast Shells, p. 95, fig. 79, 1892. Williamson, Proc. U. S.
Nat. Mus., Vol. XV, 1892, p. 198.
Shell large, oval, conical, depressed; surface cancellated with numerous radiating ridges and
concentric incremental lines; summit subcentral, the oval opening surrounded by a callus; margin
crenulated.
Dimensions. — Long, go mm.; lat. 57 mm.; alt. 20 mm.
This species is distinguishable by its large size and rather faint sculpture.
Rare in the upjier San Pedro series at Los Cerritos.
Living. — San Pedro to San Diego (Carpenter; Williamson).
Pleistocene. — San Pedro (Arnold).
Subfamily EMARGINULINjE.
Genus Fissuridea Siuainson.
Shell oval, conical, depressed, with the ape.x in iront of the center, and perforated by oblong
opening; surface radiated or cancellated; margin crenulated; callosity often truncate, sometimes
aminated.
Fissuridea incequalis Sby. is a characteristic species.
( 43 ) May 4, 1903.
338 CALIFOENIA ACADEMY OF SCIENCES.
395. Fissuridea aspera Eschscholtz.
Fisstirella aspera EsCH., Zool. Atlas, Vol. V, p. 21, PI. XXIII, fig. 5, 1833.
Glvphis aspera EsCH., Cpr., Proc. Zool. Soc, 1856, p. 223. Cpr., Brit. Assn. Rept., 1863, p. 651.
Garb, Pal. Cal., Vol. II, p. 85, 1869. Cooper, 7th Ann. Rept. Cal. St. Min., 1888,
p. 241. Keep, West Coast Shells, p. 96, fig-. 80, 1892.
Fissuridea aspera EscH., Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 197.
Shell oblong, conical; anterior and posterior slopes only very slightly convex; apical hole
anterior to center, nearly circular, the plane of its outer rim sloping considerably forward; numerous
prominent, straight, rough ribs radiate from the apical hole and produce a corrugated margin for the
shell; inner side of rim corrugated and slightly effuse; inner surface smooth.
Dimensions.— X^O'^i^. 60 mm.; lat. 42 mm.; alt. 23 mm.
Easily distingiii.sluible by its Isirge size and prominent, rough, radiating ridges
and alternating color bands. Has fewer and rougher ribs than F. marina, and a
more elliptical apical hole.
Not uncommon in the lower San Pedro series at Deadman Island and San
Pedro; common in the upper San Pedro series at Crawfish George's, and rare in the
same formation at Los Cerritos, Deadman Island, and San Pedro.
JAving. — Sitka to San Pedro (Cooper).
Pleistocene. — Santa Barbara to San Pedro (Cooper): San Pedro (Arnold).
396. Fissuridea inaequalis Sowerby.
Fissurel/a incequalis Sby., Proc. Zool. Soc, 1834, p. 126; Conch. Ill , fig. 45. Reeve, Conch.
Icon., fig. 50.
Glyphis ineequalis Sv.Y., Cpr., Brit. Assn. Rept., 1856, p. 184, PI. VII, figs. \a-^7i. Tryon, Man.
Conch., Vol. XII, p. 215, PI. XXXIV, figs. 63, 64, 1S90.
Fissurella pica Sby., Proc. Zool. Soc, 1834, p. 126; Conch. 111., Vol. II, figs. 32, 33. Reeve,
Conch. Icon., fig. 49.
Fissurella incequalis va.r. pica vSbv., Cpr., Brit. Assn. Rept., 1856, p. 184. Tryon, Man. Conch.,
Vol. XII, p. 215, PI. XXXIV, fig. 64, 1890.
Shell oblong, conical, much depressed; anterior and posterior surfaces conve.x; lateral view
of margin a line conve,\ upward (as if shell had been on a convex surface); radiating ridges numer-
ous and fine; concentric ridges numerous and nearly as prominent as the radiating ridges; the two
systems of lines giving the surface a decidedly cancellate appearance; apical hole slightly oblong,
anterior to center; inner surface smooth; inner surface of margin finely corrugated; color white.
Dimensions. — Long. 22.5 mm.; lat. 12 mm.; alt. 6 mm.
Distinguishable from other members of tliis genus occurring in this formation
by its small size and the convex appearance of the sloping sides. The specimen
described was identified by Dr. Dall.
Six specimens in the upper San Pedro series of San Pedro; also found in the
same horizon at Los Cerritos, Deadman Island, and Long Beach.
Living. — Guacomayo; Galajiagos Islands (Carpenter).
Pleistocene. — San Pedro (Arnold).
ARNOLD — THE PALEONTOLOGY AND STEATIGEAPHY OF SAN PEDRO. 339
397. Fissuridea murina {Carpenter) Dall.
G typhis dcnsiclalhraia var. imiritta Cpr., mss.
Fissurida: murma (Cpr.) Dall, Proc. U. S. Nat. Mus., Vol. VIII, 1885, p. 543; Vol. XV, 1892,
p. 197.
Glyphis deyisiclathrata RvE., Tryon, Man. Conch., Vol. XII, p. 215, PI. XXXIX, fig. 81, 1890 (pars).
Cooper, Bull. No. 4, Cal. St. Min. Bureau, Part 3, 1894, p. 27.
Shell resembles F. aspcra in general outline; apical hole nearly central, circular; radiating
ridge.s numerous and smooth, e.xcept for line incremental lines; inner margin of shell quite evenly
crenulated; color white.
Dimensions. — Long. 46 mm.; lat. 30 mm.; alt. 16 mm.
Distinguishable from F. aspera by lack of coloration, finer and more numer-
ous ribs, more central ;ui(l more nearly roniul apical hole. Smaller than tlie latter.
Dr. Dall says that this is the same species which Californian conchologists have been
calling Glijphis densiclnthrafa,hut that it is not the same as Reeve's G. dent^idnthratd.
Four specimens in the upper San Pedro series of San Pedro; found in tlie
same horizon at Deadman Island, Los Cerritos, and Crawfish George's; and in the
lower San Pedro series at Deadman Island.
Living. — San Pedro; Catalina (Williamson): Santa Barbara (Cooper).
Pleistocene. — San Pedro (Arnold) : San Joaquin Bay, Orange County (Bowers).
Genus Clypidella Sivainson.
Shell oval, rugose, slightly elevated, truncated at the anterior extremity; perforation large,
subcentral, or somewhat anterior,
Clypidella pustnlata Lam. is a characteristic species.
398. Clypidella bimaculata Bull.
Clypidella (f) bimaculala Dall, mss., in CooPER, Geol. Cat. W. C. Shells, No. 470, 1866.
Fissurellidiea bimaculata Dall, Am. Jour. Conch., Vol. VII, 1872, p. 132, PI. XV, fig. VII.
Keep, West Coast Shells, p. 97, fig. 82, 1892.
Clypidella bimaculata Dall, Gabb, Pal. Cal., Vol. II, pp. 86, 124, 1869. Cooper, 7th Ann. Rept.
Cal. St. Min., 1S88, p. 235.
Megatebeniius bimaculatus Dall, Tryon, Man. Conch., Vol. Xll, p. 183, PI. XLIV, fig. 94, 1890.
Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 198.
Shell resembles C. callomarginaia. Aperture and apical hole elliptical, the latter being
central; wide, thickened ridge on inner side of rim and on inner side of apical hole. Smaller than
C. callomarginata.
Specimens identified by Dr. Dall.
Not uncommon in the lower San Pedro series of Deadman Island and San
Pedro; rare in the upper San Pedro series of Los Cerritos and San Pedro.
Living. — Farallon Islands to Santa Barbara Islands (Cooper).
Pleistocene. — Santa Barbara; San Pedro (Cooper): San Pedro (Arnold).
340 CALIFORNIA ACADEMY OF SCIENCES.
399. Clypidella callomarginata Carpenter.
"Cfyptde//a callomarginata Cpr., Brit. Assn. Rept., 1866." Gabb, Pal. Cal., Vol. II, pp. 86, 124,
1869. Dall, Am. Jour. Conch., Vol. VII, 1872, p, 133, PI. XV, fig, 8. Cooper,
7th Ann. Rept. Cal. St. Min., 1888, p. 235. Tryon, Man. Conch., Vol. XII, p. 197,
PI. XLIV, figs. 3, 4, 5; PI- LXI, figs. 1-5, 1890.
Fissurellidcea callomarginata CpR., Keep, West Coast Shells, p. 97, 1892.
Lucapinella callomarginata Cpr., Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 198.
Shell elongate-ovate, conical, depressed; apical hole elongate-ovate, large, not central;
surface sculptured by alternating large and small radiating ridges, and prominent, concentric raised
lines; aperture elongate-ovate; margin crenulated, thickened.
Dim,ensions. — Long. 22 mm.; lat. 12 mm.; alt. 4.5 mm.
The specimen described was identified by Dr. Dall.
Rare in the lower San Pedro series of Deadman Island and San Pedro; and
in the upper San Pedro series of Crawfish George's, Los Cerritos, and San Pedro.
Living. — Lobitos to San Diego (Cooper).
Pleistocene. — San Pedro to San Diego (Cooper): San Pedro (Arnold).
Genus Fissurella Bruguiere.
Shell oval, conical, depressed, with the ape.x in front of the center, and perforated; surface
radiated or cancellated.
fissurella picta Gmel. is a characteristic species.
400. Fissurella volcano Reeve.
Fissurella volcano RvE., Icon. Conch., PL IV, fig. 2, 1849. Sby., Thes. Conch., Vol. Ill, p. 192,
fig. 87. Cpr., Brit. Assn. Rept., 1863, p. 651. Gabb, Pal. Cal., Vol. II, p. 86, 1869.
Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 240. Tryon, Man. Conch., Vol. XII,
p. 156, PI. LXII, figs. 16-1S, 1890. Keep, West Coast Shells, p. 96, fig. 81, 1892.
Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 197.
Shell oblong, conical, apical hole oblong, slightly anterior to center; numerous small radi-
ating ribs run down to the margin; margin smooth; alternating red and dark colored stripes radiate
from the apical hole; sloping surface straight.
Dimetisions. — Long. 27 mm.; lat. 19 mm.; alt. 10 mm.
Distinguishable by the coloration, which is apparent in all the Pleistocene
specimens that have been examined. Much smaller than F. as'pera Esch., which is
the only Pleistocene limpet it resembles.
Rather common in the lower San Pedro series at Deadman Island and San
Pedro; and in the upj^er San Pedro series at Deadman Island, Los Cerritos, Crawfish
George's, and San Pedro. Found in the Pleistocene at Pacific Beach, San Diego.
Living. — Santa Cruz to San Diego (Cooper).
Pleistocene. — Santa Barbara to San Diego (Cooper) : San Pedro; San Diego
(Arnold).
ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 341
Genus Puncturella Loive.
Shell conical, elevated, with the apex recurved; perforation in front of the apex, with a
raised border (septum) internally; surface cancellated.
Puncturella noachina Linn, is a characteristic species.
401. Puncturella cucullata Gould.
Rimula cucullata Gld., Proc. Bost. Soc. Nat. Hist., Vol. II, 1846, p. 159; Wilkes' Expl. Exped.,
Vol. XII, p. 268, fig. 475, 1852.
Puncturella cucullata Gld., Cpr. , Brit. Assn. Rept., 1863, p. 651. Cooper, 7th Ann. Rept. Cal.
St. Min., 1888, p. 261. Tryon, Man. Conch., Vol. XII, p. 232, PI. XLII, figs. 72-75;
PI. LXIII, figs. 38, 39, 1890.
Shell shaped like an oblique cone, with an elevated acute apex posterior to the center and
curving forward like a curved beak; sixteen to eighteen prominent radiating ribs with three to five
less prominent ribs between each of the larger; ribs muricated by fine incremental lines; fissure
narrow and narrowing upwards; aperture ovate; inner edge crenulated, furrows following the external
ridges only for short distance from ribs.
Dimensions. — Long. 22 mm.; lat. 15.5 mm.; alt. 13.5 mm.
The specimen described was identified by Dr. Dall.
Rare in lower San Pedro series of San Pedro; four specimens; also found in
Pliocene of Deadraan Island; and upper San Pedro series at San Pedro. Found in
the Pliocene at Packard's Hill, Santa Barbara.
Living. — Straits of Fuca to Monterey (Cooper).
Pleistocene. — Santa Barbara (Cooper): San Pedro (Arnold).
Pliocene. — Packard's Hill, Santa Barbara (Arnold).
402. Puncturella galeata Gould.
Rimula galeata Old., Proc. Bost. U. S. Nat. Hist., Vol. II, 1846, p. 159; Wilkes' Expl. Exped.,
Vol. XII, p. 369, fig. 476, 1852.
Puncturella galeata Gld., Cpr., Brit. Assn. Rept., 1863, p. 651. Tryon, Man. Conch., Vol. XII,
p. 230, PL XLII, figs. 62-65, 1890.
Shell erect, conical; apex central, elevated, acute, with the point hooked forward; numerous,
nearly equal, sharp raised lines radiate from the apex; incremental lines fine and numerous; fissure
narrow and small; in front of sulcus, near the summit, is a transverse rib having between it and the
formix on each side a little triangular pit.
Dimeyisions. — Long. 8.1 mm.; lat. 5.5 mm.; alt. 6 mm.
The sjjecimen described was identified by Dr. Dall.
One specimen in lower San Pedro series of San Pedro; also found in
Pliocene of Deadraan Island.
Living. — Puget Sound district (Carpenter).
Pleistocene. — San Pedro (Arnold).
342 CALIFORNIA ACADEMY OF SCIENCES.
Subclass ISOPLEURA.
Order POLYPLACOPHORA.
Superfamily EOCHITONIA.
Family LXXXVIII. CHITONID.E.
Genus Ischnochiton Gray.
Shell thin; laminffi of insertion regular, acute, neither pectinate nor serrate; eaves large;
sinus usually smooth; girdle squamose, the squama; generally striate.
Ischnochiton longicymoa Blainv. is a characteristic species.
403. Ischnochiton regularis Carpenter.
Chiton regularis Cpr., Proc. Zool. Soc, 1855, p. 232.
hchnochiton regularis Cpr., Keep, West Coast Shells, p. 107, fig. 93, 1892. Tryon, Man. Conch.,
Vol. XJV, p. 142, PI. XVIII, figs. 41, 46, 1892.
Shell depressed, elongate-oval, width half of length; valves not sharply arched; lateral areas
ornamented with concentric, slightly granular ridges and fine radiating lines; central area with
inconspicuous fine irregular lines; apex smooth; mucro longitudinally ridged with irregular raised lines.
Description partly from living shell. The only fossil rejjresentative of this
sjjecies so far reported is a perfect central valve found in the upper San Pedro series
of San Peih-o in 1894 by Dr. G. H. Ashley.
Living. — Monterey (Carpenter): West Coast (Keep).
Pleistocene. — San Pedro (Ashley).
Genus Gryptochiton Mldd. d- Gray.
Shell large; valve entirely immersed in the girdle, which is minutely fasciculately pilose.
Type, Cryptochiton stelleri Midd.
404. Gryptochiton stelleri Mkidendorff.
Chiton stelleri Miuu., Bull. Acad. St. Peters., Vol. VI, 1S46, p. 116.
Chiton (yCryptochitori) stelleri M\t>d., Mai. Ross., Pt. i, p. 93, PI. I, figs, i, 2, 1847.
Chiton amiciilatus S^\., Thes. Conch., Ill, Chitons, fig. 80.
Chiton sitkensis RvE., Icon. Conch., PI. X, sp. 55.
CryptochiloH stelleri Midd., Cpr., Brit. Assn. Rept. , 1863, p. 648. Gabb, Pal. Cal., Vol. 11, p. 87,
1869. Tryon, Struct, and Syst. Conch., Vol. II, p 346, PI. LXXXV, fig. 83, 1883.
Cooper, 7th Ann. Rept. Cal. St. Min., 18S8, p. 237. Keep, West Coast Shells, p. in,
fig- 99, 1892. Tryon, Man. Conch., Vol. XV, p. 148, PI. VII, figs. 7-13; PL VI,
fig. 6, 1893.
Chiton calif orniais Prescott, Am. Jour. Sci., 2nd Ser., Vol. XXXVIII, 1864, p. 185.
ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 343
One valve was found in the lower San Pedro series of Deadman Island, and
two in the Pliocene of the same locality. One is probably an end valve and is
distinguishable by its strong convexity, thickness, and smooth surface. It has a
.small, acute notch on each side near the end.
Dimensions. — Long. 20 mm.; lat. 30 mm.; alt. 13 mm.
Living. — Straits of Fuca to Monterey; Kamtschatka (Cooper): Hakodate,
Japan (?) (Carpenter).
Pleistocene. — San Diego (Cooper): San Pedro (Arnold).
Pliocene. — Deadman Island, San Pedro (Arnold).
Superfamily OPSICHITONIA.
Family LXXXIX. MOPALIID^.
Genus Mopalia (rraij.
Shell regular; laminae lengthened; anterior valve with six or more slits, the others with a
single slit; last valve sinulate behind; sinus narrow, mucro median, depressed; sutures indented;
girdle wide, bristly, sometimes fissured behind, sometimes projecting anteriorly.
Mopalia hlainvillei Brod. is a characteristic species.
405. Mopalia ciliata Soiverby.
Chiton muscosus Gld., Proc. Best. Soc. Nat. Hist., Vol. II, 1846, p. 145; Wilkes' Expl. Exped.,
Vol. XII, p. 313, fig. 436, 1852.
Mopalia muscosa Gld., Cpr. , Brit. Assn. Rept., 1863, p. 648.
Mopalia ciliata Sby., Keep, West Coast Shells, p. no, fig. 98, 1892. Williamson, Proc. U. S.
Nat. Mus., Vol. XV, 1892, p. 196.
Shell depressed, rather broad, oval; obliquely ridged along the back; sculpture prominent
and covering whole of surface; side areas sculptured with granulated, radiating ridges; central area
ornamented with longitudinal, granulated, raised lines; mucro median depressed, ornamented with
sharp, oblique lines which meet on middle and form an acute angle open anteriorly; anterior valve
large, semicircular, with ten granulated, elevated, radiating lines, and interspaces granulated as in
lateral areas.
Dimensions. — Long. 40 mm.; lat. ig mm.; depth 6 mm.
Description from living specimen. The only specimen of this species ever
reported in the fo.ssii state was found in the upper San Pedro series of San Pedro.
It is a perfect anterior valve, 10 millimeters wide and 5.2 millimeters long.
Living. — Vancouver to Monterey (Carpenter): San Pedro (Williamson).
Pleistocene. — San Pedro (Arnold).
344 CALIFOKNIA ACADEMY OF SCIENCES.
ARTHROPODA.
Class CRUSTACEA/
Subclass EUCRUSTACEA.
Superorcler CIRRIPEDIA.
Order THORACICA.
Family XC. BALANID.E.
Genus Balanus Lister.
Shell low, conical or cylindrical, composed of six pieces. Opercular plates subtriangular;
base membranous or calcareous.
406. Balanus concavus Bronn.
Balanus co7icavus Bronn, Italiens Tertiar-Gebilde (1S31) et Lethaea Geognostica, b, II, 3, 1155
(1838), Tab. XXXVI, fig. 12; = B. cylindraceus var. concavus Lam.; = Lepas
tintinnabuhmi Brocchi, {^fide Darwin, Monog. Cerripedia, II, p. 235, PL IV,
fig. 4a-4<?, 1854).
Shell longitudinally striped with white and pink, or dull purple, sometimes wholly white;
scutum finely striated longitudinally; internally, adductor ridge very or moderately prominent.
This is the common 2)ink barnacle of the west coast. Darwin reports this
species as fossil from Coralline crag, England; subappenine formations, near
Turin, Asti, Colle in Tuscany; Tertiary beds near Lisbon; Tertiary beds,
Williamsburg and Evergreen, Virginia; Maryland.
Sometimes found in the upper San Pedro series of San Pedro, Los Cerritos,
Crawfish George's, and Deadman Island; also reported from the lower San Pedro
series of San Pedro. Found in the Pliocene at Packard's Hill, Santa Barbara; and
at Puss School, San Diego; in the Pleistocene at Barlow's ranch, Ventura; and at
Spanish Bight and Pacific Beach, San Diego.
Living. — Panama; Peru; San Pedro, California; Philippine Archipelago;
Australia (Darwin).
Pleistocene. — San Pedro (Arnold).
' The classification and generic descriptions of this claas, unless otherwise stated, are from Eastman's Zittel's "Text-Book
of Paleontology."
ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 345
Superorder MALACOSTRACA.'
Order DECAPODA.
Suborder BRACHYURA.
Subtribe CANCROIDEA.
Section Cancrini.
Genus Cancer Linne.
Carapace transverse, subelliptical, indistinctly areolated; antero-lateral margins regularly
arcuated and armed with ten teeth; front narrow, cut into five teeth or lobes; eye-peduncles short, orbits
small, with two fissures in both upper and lower margins; antcnnules longitudinal, or nearly so; basal
antennal joint somewhat enlarged and united with the fi-ont, thus excluding the short flagellum from
the orbit; merus of the maxillipeds distally truncated, and not produced at the antero-external angle;
chelipeds subequal, the hand generally costate on the outer surface.
407. Cancer breweri Gabb.
Cancer breweri Gabb, Pal. Cal., Vol. II, p. i, PI. I, fig. i, 1869. Cooper, 7th Annual Rept. Cal.
St. Min., 1888, p. 227.
" Hand shorter, more robust, and broader proportionally than that of C. magisler Dana;
upper margin flattened and bordered by two well-defined ridges, each bearing about four tubercles;
outer surface marked by five nearly obsolete ridges minutely tuberculated; fingers shorter than in
C. magister, the movable one more curved, and both with the denticles nearly obsolete" (Gabb).
Ditnensions. — Length of hand 82 mm.
The above description Is a copy of Gabb's original. A well preserved hand
from the lower San Pedro series of Deadraan Island corresponds almost exactly with
Gabb's figure of his type. G. macjister is the common large edible crab of the Cali-
fornia coast.
Pleistocene. — San Pedro (Arnold).
Pliocene. — Calleguas ranch, Ventura County (Brewer).
1 Divisions of this suborder and generic description from "Synopsis of California Stalk-Eyed Crustacea.'* By S. J. Holmes.
Occasional Papers, Cal. Acad. Sci., No. VII, p. 47, 1900.
( 44 ) May 29, 1903.
346 CALIFORNIA ACADEMY OF SCIENCES.
VERTEBRATA.
Class PISCES.
Order ELASMOBRANCHII.
Suborder SELACHII.
Family TRYGONIDJi.
Genus Urolophus.
408. Urolophus halleri (?) Cooper.
Two stings of this species (one of the common Sting-Rays of the California
coast) were found in a perfect state of preservation in the upper San Pedro series at
San Pedro. Dr. C. H. Gilbert, who identified the specimens, said that owing to the
insufficienc}'^ of the evidence offered by the sting alone he was unable to make a
definite specific determination.
Pleistocene. — San Pedro (Arnold).
Part III. Bibliography
The following Bibliography is intended to give all of the articles which refer
either to the geology or paleontology mentioned in this paper. Inasmuch as nearly
all of the species found as fossils in the deposits at San Pedro are living at the present
time, most of the articles refer to living shells. Dr. Stearns has kindly prejJared a
complete list of his publications up to January 1, 1901, and as a complete bibliography
of his writings has never been published it will be included here under his name.
Many of the references given were taken from the Bibliography of Fossil
Mollusca, prepared by the late Dr. James G. Cooper, and published in Bulletin
No. 4 of the California State Mining Bureau.
1852. Adams, Chas. B. Catalogue of Panama Shells. An7i. N. Y. Lye. Nat. Hist., Vol. V,
1852; also separately.
Full uotes aud descriptions; no figures. Out of nearly 500 species, over 100 were new; but
very few of them extend to California, though many of the species are found living or fossil
farther north.
1835. Adams, Henry and Arthur. Various articles published in Proc. Zool. Soc, 1835 to 1876.
1853-83. The Genera of Recent Mollusca. 2 vols., 8vo, and 138 plates. London, 1853-83.
This tine systematic work contains figures aud descriptions of several West Coast mollusca.
1863. Agassiz, Alex. Descriptions of New Echinoderms. Bull. Mus. Comp. Zool.,'Wo\. I, 1863.
1874. Revision of the Echini. ///. Cat. Mus. Comp. Zool., No. 7. Cambridge, 1872-74.
1899. Anderson, F. M. The Geology of Point Reyes Peninsula. Bjtll. Dept. Geol., Ujiiv.
Cal., Vol. II, 1897, No. 5, pp. 1 19-153, PI. IV.
1902. Arnold, Delos and Ralph. The Marine Pliocene and Pleistocene Stratigraphy of the
Coast of Southern California. Jour. Geol., Vol. X, 1902, No. 2, pp. 1 17-138,
Pis. I-V, figs. 1-7.
1895. Ashley, G. H. The Neocene Stratigraphy of the Santa Cruz Mountains of California.
Proc. Cal. Aead. Sci., 2nd Ser., Vol. V, 1895, pp. 273-367, Pis. XXII-XXV.
Also issued in Lelaud Stanford Junior University Publications, Geology and Paleontology,
No. 1, 1895.
1863. Baird, William. Collections made by Dr. Lyall, Dr. Forbes, R. N., and J. K. Lord,
on the Northwest Boundary Survey, Vancouver Island, etc. Proc. Zool. Soc., 1863,
p. 66, 12 plates.
Sixteen species described, fourteen figured, but only nine seem to be new.
1863. BiNNEV, W. G. Bibliography of North American Conchology. 2 vols., 8vo.
Published by the Smithsonian Institution, 1863-64. This publication catalogues all of the
American species named by the authors quoted. Useful for books printed before I860.
(347)
348 CALIFOENIA ACADEMY OF SCIENCES.
1825-27. Blainville, D. de. Manuel de Malacologie et de Conchyliologie. 2 vols., 8vo, 190
plates. Paris, 1825-27.
1832. Living and Fossil Purpuras, etc. Atiti. Nouvelles du Mus. Paris, Vol. I, 1832,
p. 189, with plates.
1878. Bowers, Stephen. Geology of Santa Rosa Island from Notes taken by Dr. Lorenzo
G. Yates. Smithsonia7i Report for 1877, pp. 316-320.
1881. Brauns, David. Geology of the Environs of Tokio. Mem. Sci. Dept., Univ. of Tokio,
No. 4, 1881.
1829. Broderip, W. J., & Sowerby, G. B. Zool. Jour., Vol. IV, 1829, p. 359, descriptions.
Plates of same iu Zoology of Captain ^eechey's Voyage to the Pacific and Behring's Straits,
in tlie ship "Blossom," 18'25-28; published iu Loudon in 1S39, with the aid of Dr. .J. E. Gray.
1830. Species Conchyliorum. London, 1830.
Monographs of various genera; 4 to 14 colored plates.
1832-35. Descriptions of West Coast Species of Mollusks. Proc. Zool. Soc, 1832-35.
1827. Brown, Thomas. Recent Conchology of Great Britain, i vol., 4to, 62 colored plates.
Edinburg, 1827. 2nd Ed., London, 1844.
1855. Carpenter, P. P. Descriptions of (supposed) New Species and Varieties of Shells,
from the Californian and West Mexican Coasts, principally in the Collection ot
H. Cuming. Proc. Zool. Sac, 1855, pp. 228-235.
1855-57. Catalogue of the Reigen Collection of Mazatlan Mollusca in the British Museum.
Printed by order of the Trustees at the Oberliu Press, Warrington, 1855-18.57.
i856fl. First Step toward a Monograph of the Recent Species of Petaloconchus, a Genus of
Vermetidea. Proc. Zool. Soc, 1856, pp. 313-317, with woodcuts.
1856^. Monograph of the Shells collected by T. Nuttall, Esq., on the Californian Coast, in
the year 1834-5. Proc. Zool. Soc, 1856, pp. 209-229.
i856f. Descriptions of Shells from the Gulf of California, and the Pacific Coasts of Mexico
and CaHfornia. Part II. By H. A. Gould, M.D., and P. P. Carpenter. Proc. Zool.
Soc, 1856, pp. 198-208.
iS^bd. Description of New Species and Varieties of Calyptraeida;, Trochida-, and Pyra-
midellidse, principally in the Collection of Hugh Cuming, Esq. Proc Zool. Soc, 1856,
pp. 166-171.
i?,^6e. Description of New Species of Shells collected by Mr. T. Bridges in the Bay of
Panama and Its Vicinity, in the Collection of Hugh Cuming, Esq. Proc. Zool. Soc,
1856, pp. 159-166.
1856/. Notes on the Species of Hipponyx inhabiting the American Coasts, with Descrip-
tions of the New Species. Proc. Zool. Soc, 1856, pp. 3-5.
1857. Report of the Present State of our Knowledge with Regard to the Mollusca of the
West Coast of North America. Rept. Bril. Assfi. Advl. Sci., 1856, pp. 159-368,
4 plates.
1858. First Step towards a Monograph of the Csecidea, a Family of the Rostriferous
Gasteropoda. (Chiefly from the American seas.) Proc Zool. Soc, 1858, pp. 413-444.
1863a. Supplementary Report on the Present State of Our Knowledge with Regard to
the Mollusks of the West Coast of North America. Rept. Brit. Assn. Advt. Sci.,
1863, pp. 517-686.
Extra copies, with title-page, 1864.
AENOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 349
18633 Review of Prof. C. B. Adams' "Catalogue of the Shells of Panama," from the
type specimens. Proc. Zool. Soc, 1863, pp. 339-369.
1864a. Descriptions of New Marine Shells from the Coast of California. Proc. Cal. Acad.
Sd., Vol. Ill, 1864, pp. 155, 175, 207.
i864(^. Diagnoses of New Forms of Mollusks, Collected at Cape Lucas, Lower California.
By Mr. J. Xantus. Ant!. Mag. Nat. Hist., 3rd Ser., Vol. XIII, 1864, pp. 311-315,
474-479; Vol. XIV, 1864, pp. 45-49-
1864c. Contributions toward a Monograph of the Pandoridae. Proc. Zool. Soc, 1864,
pp. 596-603.
1864,65. Diagnoses of New Forms of Mollusca, from the Vancouver District. Aim. Mag.
Nat. Hist., 3rd Ser., Vol. XIV, 1864, pp. 423-429; Vol. XV, 1865, pp. 2S-32. Also
in Proc. Zool. Soc, 1865, pp. 201-204.
1865a. Diagnoses of New Species and a New Genus of Mollusks, from the Reigen Mazatlan
Collection; with an Account of Additional Specimens Presented to the British
Museum. Proc. Zool. Soc, 1865, pp. 268-273.
1865^. Descriptions of New Species and Varieties of Chitonidae and Acmsedce from the
Panama Collection of the late Prof. C. B. Adams. Proc. Zool. Soc, 1865, pp.
274-277.
1865c. Diagnoses of New Species of Mollusks, from the West Tropical Region of North
America, Principally Collected by the Rev. J. Rowell, of San Francisco. Proc Zool.
Soc, 1865, pp. 278-282.
1865^. Diagnoses of New Forms of Mollusca from the West Coast of North America.
First Collected by Col. E. Jewett. Ann. Mag. Nat. Hist., 3rd Ser., Vol. XV, 1865,
pp. 177-182 and 394-399.
1 8651?. Diagnoses of New Forms of Mollusca, Collected by Colonel E. Jewett on the West
Tropical Shores of North America. Ann. Mag. Nat. Hist., 3rd Ser., Vol. XV, 1865,
pp. 399-400.
1865/. Diagnoses des Mollusques nouveaux provenant de Californie et faisant partie du
Musee de I'lnstitution Smithsonienne. Jour, de Conch., Vol. XII, 1865, pp. 129-149.
1865//. New Species and Varieties of Mollusca, Collected by the late Dr. Kennerly in
Puget Sound. Jour. Acad. Nat. Sci. Phila., New Ser., 1865, p. 54.
1865-73. Articles on West Coast Mollusca. Am. Jour. Conch., Vols. I-VII, 1865-1873.
1866. On the Pleistocene Fossils Collected by Colonel E. Jewett, at Santa Barbara, Cali-
fornia; with Descriptions of New Species. Ann. Mag. Nat. Hist., 3rd Ser., Vol.
XVII, 1866, pp. 274-278.
1872. Mollusks of Western North America. Smithsonian Miscellaneous Collections,
Vol. X, 1872, No. 252.
Thirteen reprinted papers of Carpenter's.
1769-95. Chemnitz, J. H. (M.\rtini & Chemnitz.) Conchylien Cabinet. 4to, Niirnburg,
176910 1795.
The last date is that of Vol. XI, the oulj' one in which binomial nomenclature is used,
Martini not being au authority under Linut'au rules. A new edition begun in 1844 by Kuster,
continued by W. Kobelt and Weinkauff to 1887. Nurnburg; 4to, 1,988 colored plates.
1843. Chenu, J. C. Illustrations Conchyliologiques, etc. 79 numbers, folio, colored plates.
Paris, 1843.
Living and fossil shells.
Bibliotheque Couchyliologique, a reprint of older authors and their illustrations, including
worlis by Say, Leach, Ilatiuesque, Conrad, Martin, etc.
350 CALIFORNIA ACADEMY OF SCIENCES.
1860-62. Manuel de Conchyliologie et de Palaeontologie. 2 vols., grand 8vo, with about
50CX) engraving.s, part colored. Paris, 1860-62.
1832. Conrad, Timothy A. Fossil Shells of the Tertiary Formations of North America
(Eastern), i vol., 56 pages, 18 plates. Philadelphia, 1832.
As many West Coast fossils are very near, or identical with Eastern, they need close
comparison.
1837. Descriptions of New California Shells. Jour. Acad. Nat. Sci. Phila., Vol. VII,
1837, pp. 227 et seq., 4 plates.
The 45 new species described from California, with figures, form the first important article
on West Coast shells.
1849. Report of United States Exploring Expedition, under Commander Wilkes, Vol. X,
Geology. Philadelphia, 1849.
Plates and descriptions of Tertiary fossils from Oregon, many of which have since been
found in California.
1856. Report of Explorations and Surveys for a Railroad to the Pacific Coast. Vol. V,
Appendix 2, Fossil Shells and Recent, with 9 plates; Vol. VI, Appendix, p. 69,
5 plates. Fossils; Vol. VII, Part 2, p. 189, 10 plates. Washington, D. C, 1856.
1865-73 Am. Jour. Conch., Vols. I to VII, 1865 to 1873.
Several articles on Weat Coast shells.
i860. Cooper, William. Report of Explorations and Surveys for a Railroad to the Pacific
Coast, Vol. XII, Part 2, No. 6. Report upon Mollusca Collected on the Survey.
Washington, i860. Also separately.
jg62. Nine New Californian Marine Mollusca. Pivc. Cat. Acad. Sci., Vol. II, 1862,
pp. 202-207.
j352. On New and Rare Mollusca Inhabiting the Coast of California. Proc. Cal. Acad.
Sci., Vol. Ill, 1863, p. 57.
j35y Geographical Catalogue of the Mollusca Found West of the Rocky Mountains,
between Thirty Degrees and Forty-nine Degrees north latitude. Pamphlet, 410, 40
pages. San Francisco, 1867.
797 species named.
ig-Q^ Notes on the Mollusca of Monterey Bay, California. Am. Jour. Conch., V o\. V\,
1870, p. 42.
247 species named.
1%-jol), Note on Gadinia and Rowellia. Am. Jour. Conch., Vol. VI, 1870, p. 320.
1874. On the Tertiary Geology of California, with Notes on the Characteristic Fossils,
etc. Proc. Cal. Acad. Sci., Vol. V, 1874, pp. 172, 389, 401, 422.
i883_ Catalogue of Californian Fossils. 7th A?in. Rept. Cal. St. Min. (William Irelan.)
Sacramento, 1888.
i8go. Value of Fossils as Indications of Important Mineral Products, gth Ann. Rept.
Cal. St. Min. (William Irelan.) Sacramento, 1890.
,894a. Lists of Fossils in "Gas and Petroleum yielding Formations of the Central Valley
of California." By W. L. Watts. Bull. Cal. St. Min. Bureau, No. 3, 1894.
1894^^. Catalogue of Californian Fossils. Parts 2, 3, 4 and 5. Bull. Cal. St. Min. Bureau,
No. 4, 1894.
J897. List of Fossils in "Oil and Gas yielding Formations of Los Angeles, Ventura, and
Santa Barbara Counties." By W. L. Watts. Bull. Cal. St. Min. Bureau, No. 11,
1897, pp. 79-87.
ARNOLD — THE PALEONTOLOGY AND STKATIGRAPHY OF SAN PEDRO. 351
i86g. Dall, W. H. Materials for a Monograph of the Family Lepetidae. Am. Jour. Conch.,
Vol. V, 1869, pp. 140-150.
1870a. Review of the Family Siphonariidae. Am. Jour. Conch., Vol. V, 1870, pp. 30-41,
Pis. II, IV, V.
1870^. Materials for a Monograph of the Family Gadiniidae. Am. Jour. Conch., Vol. V,
1870, pp. 8-22.
1870^. Review of the Terebratulidie and Lingulid.e. Am. Jour. Conch., Vol. V, 1870,
pp. 88-168, Pis, VI, VIII.
1871a. On the Limpets; with Special Reference to the Species of the West Coast of
America, and to a More Natural Classification of the Group. Am. /our. Conch. ,
Vol. VI, 1871, pp. 228-282, Pis. XIV-XVII
1871^. Diagnoses of Sixty New Forms of Mollusks from the West Coast of America and
the North Pacific Ocean. Am. Jour. Conch., Vol. VII, 1871, pp. 93-160, Pis.
XIII-XVI.
1871^. Note on Gadinia. Am. Jour. Conch., Vol. VII, 1871, pp. 192-193.
1872a. Notes on Californian Mollusca. Proc. Cal. Acad. Sci.. Vol. IV, 1872, pp. 182-183.
\'i>12b. Preliminary Descriptions of New Species of Mollusks from the Northwest Coast of
America. Proc. Cal. Acad. ScL, Vol. IV, 1872, pp. 270-271 and 302-303.
1873a. Catalogue of the Recent Species of the Class Brachiopoda. Proc. Acad. Nat. Sci.
Phila., 1873, pp. 177-204.
1873^. Descriptions of New Species of Mollusca from the Coast of Alaska, with Notes on
Some Rare Forms. Proc. Cal. Acad. Sci., Vol. V, 1873, pp. 57-62.
1874a. Notes on Tertiary Fossils from the California Coast, with a List of the Species
Obtained from a Well at San Diego, California. Proc. Cal. Acad. Sci., Vol. V, 1874,
pp. 296-299.
1874^. Catalogue of Shells from Behring Strait. Proc. Cal. Acad. Sci., Vol. V, 1874,
pp. 246-253.
1877a. Report on the Brachiopoda of Alaska and the Adjacent Shores of Northwest
America. Proc. Acad. Nat. Sci. Pliila., 1877, pp. 155-170. Scientijic Results, Art.
Ill, 1877, pp. 45-62.
1877^. Preliminary Descriptions of New Species of Mollusks from the Northwest Coast of
America. Proc. Cal. Acad. Sci., Vol. VII, 1877, p. 6.
1877c. On the Californian Species of Fusus. Proc. Cal. Acad. Sci., Vol. VII, 1877, p. 5.
1878a. Descriptions of New Shells from California. Proc. U. S. Nat. Mus., Vol. I, 1878,
pp. 46-47.
1878(5. Distribution of Californian Tertiary Fossils. Proc. U. S. Nat. Mus., Vol. I, 1878,
pp. 26-30.
1878^. Report on the Limpets and Chitons of the Alaskan and Arctic Regions, etc.
Proc. U. S. Nat. Mus., Vol. I, 1878, pp. 281-344. Scientijic Results, Art. IV,
1879, pp. 63-126.
i878(^. Post-Pliocene Fossils in the Coast Range of California. Proc. U. S. Nat. Mus.,
Vol. I, 1878, p. 3.
1878^. Fossil Mollusks from Later Tertiaries of CaHfornia. Proc. U. S. Nat. Mus., Vol. I,
1878, pp. 10-16.
352 CALIFORNIA ACADEMY OF SCIENCES.
1881. On the Genera of Chitons. Proc. U. S. Nat. Mus., Vol. IV, iSSi, pp. 279-291.
1S83. List of Papers by W. H. Dall, from 1866 to 1882. 3 vols. Washington, 1883.
Kepriuts of principal papers by this writer.
1884a. Report on the Mollusca of the Commander Islands, Behring Sea, Collected by
Leonhard Stejneger in 1882 and 1883. Proc. U. S. Nat. Mus., Vol. VII, 1884,
PP- 340-349. P'- II-
18843. New or Specially Interesting Shells of Point Barrow Expedition. Proc. U. S.
Nat. Mus., Vol. VII, 1S84, pp. 523-526, PI, II.
18861a;. Contributions to the Natural History of the Commander Islands. No. 6, Report
on Behring Island Mollusca, Collected by Mr. Nicholas Grebnitzki. Proc. U. S. Nat.
Mus., Vol. IX, 1886, pp. 209-219.
1 886(5. Supplementary Notes on Some Species of Mollusks of the Behring Sea and
Vicinity. Proc. U. S. Nat. Mus., Vol. IX, i886, pp. 297-309, Pis. III-IV.
1889a. Catalogue of Shell-bearing Marine Mollusks, etc. , of Southeastern Coast of the
United States. Bull. U. S. Nat. Mus., No. 37, 1889.
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AKNOLD — THE PALEONTOLOGY AND STKATIGEAPHY OF SAN PEDKO. 353
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356 CALIFORNIA ACADEMY OF SCIENCES.
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ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 357
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1871(5;. Description of a New Species of Monocera from California, with Remarks on the
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358 CALIFOENIA ACADEMY OF SCIENCES.
i872fl. Description of a New Species of Mangelia from California. Proc. Cal. Acad. Sri.,
Vol. IV, 1872, p. 226, with figure.
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1872/". The Californian Trivia and Some Points in Its Distribution. Afii. Nal., Vol. VI,
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i873«. Descriptions of a New Genus and Two New Species of Nudibranchiate MoUusks
from the Coast of California. Proc. Cal. Acad. Sci., Vol. V, 1873, pp. 77-78, with
figures.
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1873/. Shells Collected at San Juanico, Lower California, by William M. Gabb. Proc.
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figures.
Also in Globus, Braunschweig, Germany, of about same date; without credit.
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pp. 185-187, with plate. Am. Nat., Vol. XI, Feb., 1877, pp. 100-102.
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1877(5. Aboriginal Shell Ornaments, and Mr. F. A. Barber's paper thereon. Am. Nat.,
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1878. Description of a New Species of Dolabella from the Gulf of California, with Remarks
on Other Rare or Little Known Species from the Same Region. Proc. Acad. Nat.
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1879a. Remarks on Fossil Shells from the Colorado Desert. Afn. Nat., Vol. XIII, 1879,
pp. 141-154; several figures.
Read before the California Academy of Sciences.
1879^. Description of a New Species or Variety of Land Snail from California (Helix cir-
cumcarinata). An7i. N. Y. Acad. Sci., Vol. I, 1879, pp. 316-317, 3 figures.
ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 359
i88ra. Observations on Planorbis; are the Shells of Planorbis Dextral or Sinistral ? On
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1 88 1, pp. 92-110, with 27 figures.
i88ii5. Mya arenaria in San Francisco Bay. Am. Nat., Vol. XV, May, 1881, pp. 362-366.
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American Land Snails, etc. Ann. N. Y. Acad. Set., Vol. II, i88r, pp. 129-139.
1882a. Verification of the Habitat of Conrad's Mytilus bifurcatus. Proc. Acad. Nat. Set.
Phila., 1882, pp. 241-242.
1882^. On the History and Distribution of the Fresh-Water Mussels and the Identity of
Certain Alleged Species. Proc. Cal. Acad. Set., November 20, 1882, 21 pages and
figures.
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Physas of Indio; Part II. Anodonta californiensis in a New Locality. Am. Nat.,
Vol. XVII, Part 2, October, 1883, pp. 1014-1020.
Read before the Califoruift Academy of Scieuces, June 5, 1SS3.
i883<5. The Edible Clams of the Pacific Coast, and a Proposed Method of Transplanting
Them to the Atlantic Coast. Bn/t. U. S. Fish Com., Vol. Ill, 1883, pp. 353-362,
with several figures.
Letter to Prof. Spencer F. Baird, U. S. Fish Commissioner, October 14, 1882.
1883^. Description of a New Hydrobinoid Gasteropod from the Mountain Lakes of
Nevada, with Remarks on Allied Species and the Physiographical Features of Said
Region. Proc. Phil. Acad. Nat. Set. Phila., 1883, pp. 171-176, with figures.
1883a'. Fresh-Water Pearl Mussels. Mining and Scientific Press, San Francisco, April 7,
1883.
1885a. The Giant Clams of Puget Sound. Forest and Stream, May 28, 1885.
Read at the Washington, D. C, meeting of the American Fisheries Society, April, 1S65.
1885^5. The Helicidae of the John Day Fauna. Contained in Dr. Charles A. White's
paper, "On Marine Eocene, Fresh- Water Miocene, and other Fossil Mollusca of
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1886. The Teredo, or Ship-worm. Am. A'a/., February, 1886, pp. 131-136, with figures.
From letter to Prof. Spencer F. Baird, Society Smithsonian Institution.
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1887, pp. 297-334, Pis. I-IX, and numerous text-figures.
i8S9a. Helix (Stenotrema) hirsuta Say on the West Coast. Nautilus, Vol. — , November,
1889, pp.—.
1889^. Notice and Comments on the Distribution of Planorbis (Helisoma) bicarinatus Say.
J Vest American Scientist, September, 1889.
1890a. Descriptions of New West American Land, Fresh-Water and Marine Shells, etc.
Scientific Results of Explorations by the U. S. Fish Commission Steamer "Albatross."
Proc. U. S. Nat. Mus., Vol. XIII, 1890, Pis. XV-XVII, pp. 205-225.
1890^. On the Nishinom Game of " Ha " and the Boston Game of "Props." Am.
Anthropologist, October, 1890, pp. 353-358, with figures.
1891a. ^List of American Land and Fresh-water Shells Received from the U. S. Depart-
ment of Agriculture, etc. Proc. U. S. Nat. Mus., Vol. XIV, iSgi, pp. 95-106.
360 CALIFORNIA ACADEMY OF SCIENCES.
18913. List of Shells Collected on the West Coast of South America, Principally between
Latitudes 7° 30' S., and 80° 49' N., by Dr. W. H. Jones, U. S. Navy. Proc. U. S.
Nal. Mus., Vol. XIV, 1891, pp. 307-335.
iSgic. Notes on the Sculpture of American Limnteas, etc. Nautilus, Vol. IV, March,
1891, pp. 121-124.
1892^. Patula strigosa Gould, in Arizona. Nautilus, Vol. VI, May, 1892, p. i.
18923. Preliminary Descriptions of New Molluscan Forms from West American Regions.
Nautilus, Vol. VI, December, 1892, pp. 85-89.
1893^. Description of a New Species of Nassa (Nassa brunneostoma) from the Gulf of
California. Nautilus, Vol. VII, May, 1893, PP- lo-ii.
i893(^. Report on the Land and Fresh-water Shells of the Death Valley Expedition.
North Avi. Fauna, No. 7, 1893, pp. 269-283.
Issued by U. S. Dept. Agric, Division of Ornithology and Mammalogy.
i893(:. Preliminary Report on the Molluscan Species Collected by the United States
Scientific Expedition to West Africa in 18S9-90. Proc. U. S. Nat. A/us., Vol. XVI,
1893. PP- 317-339-
1893^. On Rare or Little Known Mollusks from the West Coast of North and South
America, with Descriptions of New Species. Proc. U. S. Nat. Mus., Vol. XVI,
1893. PP- 341-352. PI- I-
1893^. Report on the Mollusk Fauna of the Galapagos Islands, with Descriptions of New
Species. Scientific Results of Explorations by the U. S. Fish Commission Steamer
"Albatross." Proc. U. S. Nat. Mus., Vol. XVI, 1893, pp. 353-450, Pis. LI-LII.
1893/". Notes on Recent Collections of North American Land, Fresh-water, and Marine
Shells, Received from the U. S. Department of Agriculture. Proc. U. S. Nat. Mus.,
Vol. XVI, 1893, PP- 743-755-
1894(1. Triodopsis -j- Mesodon, Distribution, etc. Nautilus, Vol. VIII, May, 1894,
pp. 6-8.
1894^, 99. Urosalpinx cinereus in San Francisco Bay. Nautilus, Vol. VIII, June, 1894,
pp. 13-14; Vol. XII, Feb., 1899, p. 112.
1894c Helix (Arionta) coloradoensis: — A New Locality. Nautilus, Vol. VIII, July,
1894, p. 29.
i894(/. The Shells of the Tres Marias and other Localities along the Shores of Lower
California and the Gulf of California. Proc. U. S. Nat. Mus., Vol. XVII, 1894,
pp. 139-204.
1894^. Mollusk Fauna of the Galapagos Islands. West American Scientist, April, 1894.
1895. A New Variety of Ocinebra circumtexta Stearns. Nautilus,\o\.\y^,]\xn^, 1895, p. 16.
1897. ■ Uvanilla regina — A New Locality. Nautilus, Vol. XI, May, 1897, PP- i-2-
1898a. ■ Description of New Species of ActJeon from the Ouarternary Bluffs of Spanish
Bight, San Diego, California. Proc. U. S. Nat. Mus., Vol. XXI, 1898, pp. 297-299,
with figures.
Also preliminary descriptions in Nnuliltis, Vol. XI, June, 1897, pp. 14-15.
1898^5. Notes on Cytherea (Tivela) crassatelloides Conrad, with Descriptions of Many
Varieties. Proc. U. S. Nat. Mus., Vol. XXI, 1898, pp. 371-378, Pis. XXIII-XXV.
1899a'. Crepidula convexa Say, var. glauca Say, San Francisco Bay. Nautilus, Vol. XIII,
May, 1899, p.f8.
ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 361
1899(5. Natural History of the Tres Marias Islands, Mexico. Nmitihis, Vol. XIII, June,
1899, pp. 19-20.
Also in Science, N. S., Vol. X, 1S99, No. 239, p. 1-21.
A criticism of Nelson and Goldman's paper in X'. A. Fauna, No. 14.
i899<:. Dona.x stultorum Mawe: — Conrad's Species, Cytherea crassatelloides. Nautilus,
Vol. XIII, November, 1899, pp. 12>'lb-
Contains bibliogr.iphy of this species.
1899^^. Abalone Fishery in California: — Protective Regulation. NauHlus, Vol. XIII,
November, 1899, p. 81.
i899(f. Modiola plicatula Lamarck, in San Francisco Bay. Naulihcs, Vol. XIII, Decem-
ber, 1899, p. 86.
See also, Nautilus, Vol. XII, 189S, pp. 102-103.
1899/ Description of a New Variety of Haliotis from California, with Faunal and
Geographical Notes. P?oi:. U. S. Nat. il/iis.. Vol. XXII, 1899, pp. 139-142.
Also, Nautilus, Vol. XII, 1899, pp. 106-107.
1900^?. Exotic Mollusca in California. Science, N. S., Vol. XI, 1900, No. 278, pp. 655-659.
1900/J. Notes on the Saxidomi of the West Coast. Naiitiltis, Vol. XIV, May, 1900,
PP- 1-3-
1900C. The Fossil Shells of the Los Angeles Tunnel Clays. Science, N. S., Vol. XII,
1900, No. 294, pp. 247-250.
1900a'. Vallonia pulchella Miill., in Los Angeles and elsewhere in California. Nautilus,
Vol. XIV, October, 1900, pp. 65-67.
1900^'. Fossil Land-Shells of the John Day Region, with Notes on Related Living Species.
Proc. Wash. Acad. Sci., Vol. II, 1900, pp. 651-660, PI. XXXV.
1850-52. Stimpson, William. Descriptions of Marine Mollusks. Proc. Bost. Soc. Nat. Hist.,
Vol. Ill, 1850; Vol. IV, 1851-1852.
1857. Crustacea and Echinoderms of the Pacific Coast, 1S57.
1820-33. SwAiNSON, William. Zoological Illustrations. The shells in 5 parts, 4to, 40 colored
plates. London, 1820-1833.
1834. Exotic Conchology, or Drawings of Rare Shells, etc. 4to, 48 plates. London, 1834.
Second edition by Hauley, 1841.
1855. Trask, J. B. Descriptions of Californian Fossil Shells. Proc. Cal. Acad. Sci., Vol. I,
1855, pp. 40-42.
1862. Tryon, Geo. W. A Monograph of the Order Pholadacea, etc. i vol.,8vo, i plate.
Philadelphia, 1862.
1865-72. Editor American Journal of Conchology. 1865-1872. 7 vols., 8vo, plates.
1879-95. Manual of Conchology, Structural and Systematic. Philadelphia, 1879-1895.
Sixteen volumes on marine mollusks, twelve other volumes on land shells.
1882-84. Structural and Systematic Conchology. 3 vols. Philadelphia, 1882-1884.
1S33. Valenciennes, A. Recueil d' Observations de Zoologie, etc. Par Al. de Humboldt et
A. Bonpland. Vol. II. Paris, 1833.
1846. Voyage au tour du Monde sur la "Venus" pendant les annees 1836-1839. Par
M. du Petit Thouars. 24 plates. Issued in 1846.
1899. Vaughan, T. W. a New Species of Caryophyllia from California. Proc. U. S. Not.
A/us., Vol. XXII, 1899, pp. 199-203.
( 46 ) June 2, 1903.
362 CALIFORNIA ACADEMY OF SCIENCES.
1900. The Eocene and Oligocene Coral Faunas of the United States, etc. U. S. Geol.
Siirv., Monograph XXXIX.
1894. Watts, W. L. The Gas and Petroleum Yielding Formations of the Central Valley of
California. Bull. Cal. St. Min. Bureau, No. 3, 1894.
1897. Oil and Gas Yielding Formations of Los Angeles, Ventura, and Santa Barbara
Counties. Bull. Cal. St. Min. Bureau, No. 11, 1897.
1900. Oil and Gas Yielding Formations of California. Bull. Cal. St. Mm. Bureau,
No. 19, 1900.
1865. Whitney, J. D. Geological Survey of Califor7iia. Vol. I, Geology. Philadelphia, 1865.
1892. Williamson, Mrs. M. B. An Annotated List of the Shells of San Pedro Bay and
Vicinity. Proc. U. S. Nat Mus., Vol. XV, 1892, pp. 179-220, Pis. XIX-XXIIL
1902. A Monograph on Pecten aequisulcatus Carpenter. Bull. So. Cal. Acad. Set.,
Vol. \, No. 5, May i, 1902, pp. 51-64, Pis. IV-VL
1859^. Wood, William. General Conchology. Royal 8vo, 59 colored plates. Lon-
don, 1859.
1859(5. Index Testaceologicus; Catalogue of Shells According to the Linnaean System.
8vo, 2,300 colored figures. London, 1859.
1886-87. Wood, Searles V. Monograph of the Crag Mollusca. 410, 5 parts, 81 plates.
London, 1886-1887.
1851. Woodward, S. P. A Manual of the Mollusca; Recent and Fossil Shells, i vol.,
i2mo, 25 plates and many woodcuts. London, 1857.
Later editiou by R. Tate.
1889. Yates, L. G. Stray Notes on the Geology of the Channel Islands. The Mollusca of
the Channel Islands of California. Insular Floras, gth Aim. Rept. Cal. St. J^fin., 1889.
364 CALIFORNIA ACADEMY OF SCIENCES.
EXPLANATION OF PLATE L
(all figures magnified.)
Fig. I. Turbonilla ( Lancca) pentalopha Dall & Bartsch. Type specimen. Longitude
8.5 mm.; x6. . 274
Fig. \a. Same. Nuclear whorls more enlarged. 274
Fig. 2. Turbonilla (Pyrgolampros) gibbosa Carpenter. Longitude 5.6 mm. ; X9.3- 279
Fig. 2a. Same. Nuclear whorls more enlarged. 279
Fig. 3. Odosto7nia ( Oscilla) esquisculpta Carpenter. Type specimen, not fully mature.
Longitude 2 mm. ; xi3. 284
Fig. 3a. Same. Nuclear whorls more enlarged. 284
Fig. 4. lurbonilla ( Pyrgisais) auricoma Dall & Bartsch. Type specimen. Longitude
7.2 mm.; x6.2. 274
Fig. 4a. Same. Nuclear whorls more enlarged. 274
Fig. 5. Tit? bonilla (Pyrgolampros) lozvei Da'L'L & ^ARTSCU. Type specimen. Longitude
7.2 mm.; x6.2. 278
Fig. 5a. Same. Nuclear whorls more enlarged. 278
Fig. 6. Odostomia ( Oscilla) grammatospira Dall & Bartsch. Tj'pe specimens. Lon-
gitude 5.3 mm.; xio. 285
Fig. ba. Same. Nuclear whorls more enlarged. 285
Fig. 7. Turbonilla (Pyrgolampros) arnoldi Dall & Bartsch. Type specimen. Lon-
gitude 7.6 mm. ; x6.2. 279
Fig. 8. Odostomia ( Chrysallida) diegensis Dav.\^ & 'RA.v.TScn. Type specimen; the lower
right-liand portion of the aperture defective. Longitude 4 mm.; xu- 284
Fig. 9. Turbonilla (Pyrgolampros ) adleri Dall & Bartsch. Type specimen; the apex
defective. Longitude 9.3 mm.; X5- 280
Fig. 10. Turbonilla (Strioturbonilla) iorquala var. stylina Carpenter. Longitude 8 mm.;
X7-25. 272
Fig. \oa. Same. Nuclear whorls more enlarged. 272
Fig. II. Odostomia (Amaura) tiuciformis vat. avellana Carpenter. Type specimen.
Longitude 9. 1 mm.; X5. 283
Fig. 12. Odostomia ( Evalea) stearnsii Dall & Bartsch. Type specimen. Longitude
5.2 mm.; X9. 2. 282
Fig. 13. Odostomia (Amaura) pupi/ormis Carpenter. Type specimen. Longitude
6.5 mm.; X7. 283
Fig. 14. Odostomia tenuis Carpenter. Longitude 5.7 mm.; x8. 281
Fig. 15. Odostomia (Evalea) gouldii Carpenter. Longitude 5 mm.; X9. 282
Me^idirs Cal Acad. Sci. Vdl. hi.
3«
4<»
[AhndldJ Plate I
5 ct
6 «•
13
14-
PHUIO ■UEH.HBnTDM ft HEY, B J".
366 CALIFORNIA ACADEMY OF SCIENCES.
EXPLANATION OF PLATE IL
(all figures MAGNIFIED.)
Tiirbonil/a ( Lancea) tridenlata Carpenter. Longitude 12. 8 mm.; X5. 273
Same Nuclear whorls more enlarged. 273
Turbonilla (Pyrgiscus) subcuspidata Carpe.VTER. Type specimen. Longitude
6 mm.; xg. 277
Same. Nuclear whorls more enlarged. 277
Turbonilla ( Pyrgolampros) lowei var. pedroana Dall & Bartsch. Type speci-
men. Longitude 5.5 mm.; xio. 279
Same. Nuclear whorls more enlarged. 279
Turbonilla lorquata Gould. Longitude 10.6 mm.; x6. 271
Same. Nuclear whorls more enlarged. 271
Turbonilla stearnsii Dall & Bartsch. Type specimen. Longitude 9.2 mm.;
X6.7. 271
Same. Nuclear whorls more enlarged. 271
Turbonilla ( Pyrgiscus) crebrifilata Carpenter. Longitude 5.4 mm.; xto.7. 276
Same. Nuclear whorls more enlarged. 276
Turbonilla (Pyrgiscus) tenuicula Gould. Longitude 6.1 mm.; xg. 275
Same. Nuclear whorls more enlarged. 275
Fig. 8. Ttirbonilla ( Pyrgisculus) laminata Carpenter. Longitude 6.8 mm.; xg. 277
Fig. 8a. Same. Nuclear whorls more enlarged. 277
Fig.
I.
Fig.
\a.
Fig.
2.
Fig.
ia.
Fig.
3-
Fig.
3«-
Fig.
4-
Fig.
4a.
Fig.
5-
Fig.
5«-
Fig-
6.
Fig.
ba.
Fig.
7-
Fig.
^a.
Mehqirs Cal^Acad. Sci. Vdl. iii.
[AhndldJ Fiate II.
la.
i«-
puoTQ -iiTH HanroK s bev. s j;
368 CALIFORNIA ACADEMY OF SCIENCES.
EXPLANATION OF PLATE IIL
Fig. I. Paracyatkus pedroensis Vaughan. View of calice. Greater diameter 12 mm.;
X2.8. 88
Fig. \a. Same. Upright view of corallum. Height 18 mm.; xi.2. 88
Fig. 2. CaryophyUia ca/ifornica Vkughan. ViewofcaHce. Greater diameter 1 1.5 mm. ;
X2.7. 87
Fig. 2a. Same. Upright view of corallum. Height 13 mm.; xi-2. 87
Fig. 3. Caryophyllia pedroe?isis V KVGHkN. View of calice. Greater diameter 13.5 mm. ;
X2.6 87
Fig. T,a. Same. Upright view of corallum. Height 25.5 mm.; xi.2. 87
Fig. 4. CaryophylUa anioldi V A\!onA.n. Upright view of corallum. Height 16.5 mm.;
X2.5.
Fig. 4a. Same. View of calice. Greater diameter 16 mm.; X2.5. 86
Fig. 5. Turbonilla ( Pyrgiscus) lalifH>idiaDKi.i. & ^KKTSCH. Type specimen. Longitude
5.8 mm.; X7.4. 275
Fig. 5*. Same. Nuclear whorls more magnified. 275
86
Memoirs Cal.Acad.5ci.Vdl. in.
[Arndluj Plate III
3 a
■to.
PHara-UTH BHITTDN ft KEY. ST.
370 CALIFORNIA ACADEMY OF SCIENCES.
EXPLANATION OF PLATE IV.
Fig. I. Nassa cerritensis, sp. nov. Upper San Pedro series, Los Cerritos. Type
specimen. Longitude 31 mm.; Xi.S- 231
Fig. 2. Volvula cylindrica Carpenter. Lower San Pedro series, Deadman Island. Lon-
gitude 7 mm.; X2. 191
Fig. 3. Nassa ca/iforttiana CoNRAD. Upper San Pedro series, San Pedro. Longitude
38 mm.; X3- 231
Fig. 4. Bitlhim californiawi Dall & Bartsch. Lower San Pedro series, San Pedro.
Longitude 5.6 mm. ; X4. 291
F'&- 5- Siphonalia kellettii Forbes. Upper San Pedro series, San Pedro. Longitude 112
mm. ; natural size. 229
Fig. 6. Nassa versicolor var. hooveri, var. nov. Upper San Pedro series, San Pedro.
Type specimen. Longitude 14 mm. ; X2.7. 362
Fig. 7. Fustis riigosus Trask. Lower San Pedro series, Deadman Island. Longitude
50 mm. ; X1.3. 226
Fig. 8. Seila assintilata C. B. Adams. Lower San Pedro series, San Pedro. Longitude
ID mm.; X4- 290
Fig. 9. Marginella ( Volvarina) varia Sovverbv. Lower San Pedro series, Deadman
Island. Longitude 9.2 mm. ; X2-6. 222
Fig. 10. Mitromorpha internicdia, sp. nov. Lower San Pedro series, Deadman Island.
Type specimen. Longitude 9.6 mm.; X4- 223
Fig. II. Bitiimn riigatum Carpenter. Upper San Pedro series, San Pedro. Longitude
13 mm ; X3-i- 295
Fig. 12. Rissoa acutelirata Carpenter. Upper San Pedro series, San Pedro. Longitude
2.1 mm.; X6.7. 305
Fig. 13. Ttirri/el/a Jewe/tii C\K?B.nTRTL. Pliocene, Deadman Island. Longitude 69 mm.;
natural size^ 300
Fig. 14. Odostomia ( /vara) lerricula (Carpenter) D. & B. Lower San Pedro series,
Deadman Island. Longitude 4 mm.; X6-7- 285
Fig. 15. Fusus barbare7isis Trask. Pliocene, Deadman Island. Longitude 50 mm.; X1.5. 224
Memoirs CalAcad^ 5ci . Ydl. hi.
[Arndkd] Plate T/
13
4
M'm
?liDTQUTH BR'.TTITi t HTV 5T
372 CALIFORNIA ACADEMY OF SCIENCES.
EXPLANATION OF PLATE V.
Fig. I. Ocinebra barbarensis Gabb. Lower San Pedro series, Deadman Island. Lon-
gitude 19 mm.; X2. 254
Fig. 2. Ocinebra poiilsoni Nuttall. Upper San Pedro series, San Pedro. Longitude
31 mm. ; X2.7. 260
Fig. 3. Scala tincta Carpenter. Upper San Pedro series, San Pedro. Longitude 19
mm.; X2. 265
Fig. 4. Scala indianoium Carpenter. Upper San Pedro series, San Pedro. Longi-
tude 21 mm.; X2. 264
F'g- 5- Ocinebra lurida var. cerriiensis, var. nov. Upper San Pedro series. Crawfish
George's. Type specimen. Longitude 17 mm.; Xi.3. 258
Fig. 6. Colianbel/a (^^sopus) chrysalloidea Carpenter. Upper San Pedro series, San
Pedro. Longitude 11 mm.; X 2. 237
Fig. 7. Pleuroioma ( Borsonia) bartsc/ii, sp. nov. Lower San Pedro series, Deadman
Island. Short variety. Longitude 14 mm.; Xi-3- 200
Fig. 8. Drillia hcmphilli Stearns. Upper San Pedro series, San Pedro. Longitude 16
mm.; X2.5. 204
Fig. g. Ocinebra keepi, sp. nov. Upper San Pedro series, Deadman Island. Type
specimen. Longitude 35 mm.; X2. 256
Fig. 10. Drillia inermis Hinds. Upper San Pedro series, San Pedro. Longitude 22 mm.;
Xi.25. 205
Fig. II. Amphissa ventricosa, sp. nov. Lower San Pedro series, Deadman Island. Type
specimen. Longitude 13 mm.; X2. 242
Fig. 12. Ocinebra lurida var. aspcra Baird. Upper San Pedro series, San Pedro. Lon-
gitude 28 mm.; X2. 257
Fig. 13. Margarita optabilis var. nodosa, var. nov. Lower San Pedro series, San Pedro.
Type specimen, tilted back. Altitude 6.9 mm.; X4. 332
Fig. 14. Margarita optabilis var. knechti, var. nov. Lower San Pedro series, San Pedro.
Type specimen, tilted back. Altitude 8 mm. ; X3- 332
Fig. 15. Ocinebra micheli Ford. Upper San Pedro series. Crawfish George's. Longitude
16 mm.; X2.5. 259
Fig. 16. Margarita parcipicia var. pedroana,vAr. nov. Lower San Pedro series, San Pedro.
Type specimen, tilted back. Altitude 5.5 mm.; X4. 333
Memoirs Cal.Acad. 5ci. Vdl. hi.
[ArndldJ FlkteY
%^
PHOTQ -UTH HRnrCM K HEY. ST
374 CALIFORNIA ACADEMY OF SCIENCES.
Fig.
2.
Fig.
3-
Fig.
4
Fig.
5-
Fig.
6.
EXPLANATION OF PLATE VL
Fig. I. Tritoninm ( Pricne) oreg07iensis Redfielo. Pliocene, Deadman Island. Longi-
tude I02 mm.; natural size. 286
Pleurotoma ( Borsonia) dalli, sp. nov. Lower San Pedro series, Deadman Island.
Type specimen. Longitude 23 mm. ; X2. 201
Mangilia itilerfossa var. pedroana, var. nov. Lower San Pedro series, Deadman
Island. Type specimen. Longitude 6 mm.; XS- 213
Ttophon ( Borco/rophon) shiarti Smith. Pliocene, Deadman Island. Longitude
30 mm.; X2. 252
Trophon ( Boreotrophon) orpheus var, pmairsor, var. nov. Pliocene, Deadman
Island. Type specimen. Longitude 15 mm.; X2.7. 253
Trophon ( Boreotrophrn) crrritetisis, sp. nov. Lower San Pedro series, Deadman
Island. Type specimen. Longitude 32 mm.; X2. 249
Fig. 7. Columbella (Alsopns) oldroydi, sp. nov. Lower San Pedro series, Deadman
Island. Type specimen. Longitude 8.5 mm.; X2.6. 238
Fig. 8. Trophon (Boreotrophon) gracilis Perry. Pliocene, Deadman Island. Longitude
26 mm.; X2. 250
Fig. 9. Trophon ( Boreotrophoii) mulHcosfatus EsCHSCHOLTZ. Lower San Pedro series,
Deadman Island. Longitude 10 mm.; X2.6. 251
Fig. 10. Trophon (Boreotrophon) scalariformis GouLD. Lower San Pedro series, Deadman
Island. Longitude 15.5 mm.; X2-6. 252
Fig. II. Bittitim williamsoni, sp. nov. Upper San Pedro series, San Pedro. Type speci-
men. Longitude 2.9 mm.; X7-2. 295
Fig. 12. Trophon (Boreotrophon) pedroana, sp. nov. Lower San Pedro series, Deadman
Island. Type specimen. Longitude 12 mm.; X3-3. 251
Fig. 13. Pteurototna ( Spirolropsis) sniithi, sp. nov. Pliocene, Deadman Island. Type
specimen. Lonj^jitude 36 mm.; X1.5. 216
Fig. 14. Bittium (Styliferina) temcisadpta Carpenter. Lower San Pedro series, Deadman
Island. Longitude 6.1 mm.; X4. 296
Fig. 15. Mangilia intrrlirata Stearns. Lower San Pedro series, Deadman Island. Lon-
gitude 9.1 mm.; XS- 213
Fig. 16. Mangilia oldroydi, sp. nov. Lower San Pedro series, Deadman Island. Type
k specimen. Longitude 16. 1 mm.; X2.5. 213
Fig. 17. Mangilia scutpliirataT) A'Li.. Pliocene, Deadman Island. Longitude 1 1 ram ; X 3- 214
Memoirs Cal km. Sci . Vdl. hi.
[Arnold J Plate ^71.
15
PEDin -UTH HBTTTCS It SEY. ST.
376 CALIFOKNIA ACADEMY OF SCIENCES.
EXPLANATION OF PLATE VIL
Fig. I. Murex ( Chicorejis) leea7ius Y)p^\A,. Upper San Pedro series, San Pedro. Longitude
55 mm.; Xi.3- 243
Fig. 2. Solaris lla per amabilis Carpenter. Pliocene, Deadman Island. Altitude 14 mm.;
Xi-5- 335
Fig. 3. Pleurotoma ( Dolichotoma) cooperi, sp. nov. Upper San Pedro series, San Pedro.
Longitude 64 mm. ; natural size. 203
Fig. 4. Admele gracilior Carpenter. Lower San Pedro series, Deadman Island. Lon-
gitude 10.5 mm. ; X3-3. 219
Fig. 5. Cancellaria tritoyiidea Gabb. Upper San Pedro series, San Pedro. Longitude
90 mm.; natural size. 218
Fig. 6. Chrysodomus tabulalus Baird. Pliocene, Deadman Island. Longitude 80 mm.;
natural size. 228
Fig. 7. Chrysodomus rectirostris Carpenter. Lower San Pedro series, Deadman Island.
Longitude 28 mm.; X2. 228
Fig. 8. Cancellaria cooperi Gabb. Upper San Pedro series, San Pedro. Longitude
80 mm.; natural size. 217
Fig. 9. Mangilia angulata Carpenter. Lower San Pedro series, Deadman Island. Lon-
gitude 8 mm.; X3-6. 212
Fig. 10. Bela fidicula Gould. Lower San Pedro series, Deadman Island. Longitude
1 1 mm.; X4- 209
Fig. II. Solariclla cidaris Carpenter. Pliocene, Deadman Island. Altitude 42 mm.;
natural size. 334
;'L Acad. 5ci. Vol. Ill
[Arnold] Plate VII
f^-
.-^X
"^v
s^«f
^BTO -ilTK BIUTTOK «: HEY. B F.
378 CALIFORNIA ACADEMY OF SCIENCES.
EXPLANATION OF PLATE VIIL
Fig. I. Mavgilia pamei, sp. nov. Lower San Pedro series, Deadman Island. Type
specimen. Longitude 12.5 mm ; X3-4. 214
Fig. 2. Palndestrina curia, sp. nov. Lower San Pedro series, San Pedro. Type specimen.
Longitude 3.8 mm.; X7. 305
Fig. 3. Paludestrina stokesi, sp. nov. Lower San Pedro series, San Pedro. Type speci-
men. Longitude 4.6 mm.; X 5 4- 305
Fig. 4. Dentalium indianonim Carpenter. Lower San Pedro series, Deadman Island.
Longitude 38 mm.; natural size. 186
Fig. 5. Drillia renaiidi, sp. nov. Lower San Pedro series, Deadman Island. Type speci-
men. Longitude 16 mm.; X3. 208
Fig. 6. C{zciim californicum Dall. Lower San Pedro series, Deadman Island. Longitude
2.9 mm.; X5.8. 297
Fig. 7. Dri/lia merriatni, sp. nov. Lower San Pedro series, Deadman Island. Type
specimen. Longitude 14 mm.; X3-2. 207
Fig. 8. Bulla quoyi Gray. Upper San Pedro series, San Pedro. A young specimen.
Longitude 8 mm.; X3- '93
Fig. 9. Eiipleura murici/ormis var. curia, var. nov. Upper San Pedro series, San Pedro.
Type specimen. Longitude 15 mm.; X3.2. 249
Fig. 10. Ccscum crebricinctian Carpenter. Lower San Pedro series, San Pedro Bluff.
Longitude 5.5 mm.; X6. 298
Fig. II. Lacuna solidiila (Loven) Carpenter. Upper San Pedro series, San Pedro. A
somewhat decorticated specimen. Longitude 10 mm.; X2.5. 303
Fig. 12. Dentalium pse^idohexagonum Dall. Lower San Pedro series, Deadman Island.
Longitude 15.5 mm. ; X3' 186
Fig. 12a. Sectional view of same; X3- 186
Fig. 13. Drillia pudica Hinds. Upper San Pedro series, San Pedro. Longitude 11 mm ;
X3-5- 208
Fig. 14. Bela saiicta-mottica, sp. nov. Lower San Pedro series (Pleistocene), Port Los
Angeles. Type specimen. Longitude 12 mm.; X3. 210
Fig. 15. Cadulus nitentior Carpenter. Lower San Pedro series, Deadman Island. Lon-
gitude 10 mm.; X3.3- 187
Fig. 16. CcBcum inagnum Stearns. Lower San Pedro series, Deadman Island. Longitude
4.7 mm.; X5-3- 298
Fig. 17. Drillia johnsoni, sp. nov. Upper San Pedro series, San Pedro. Type specimen,
apex broken olT. Longitude 29 mm. ; X2. 206
Fig. 18. Haininca virescens .Sowerby. Upper San Pedro series, San Pedro. Longitude
7 mm.; X3-25- '94
Mehdirs D\l.Acad.5cl Vdl.iii.
[AhndldJ Hate VIII
if"
16
14
12 «
FHDXOrUrH BHIITON R HEY. ST.
580 CALIFORNIA ACADEMY OF SCIENCES.
EXPLANATION OF PLATE IX.
Fig. I. Pleurotoma ( Borsonia) bartschi, sp. nov. Lower San Pedro series, Deadman
Island. Type specimen. Longitude 18.5 mm.; X3-4- 200
Fig. 2. Bitlium qiiadrijilaiiim Carpenter. Lower San Pedro series, Deadman Island.
Longitude 10 mm.; X3- 292
Fig. 3. Ma7igilia striosa C. B. Adams. Upper San Pedro series, Los Cerritos. Longitude
9.4 mm.; X3- 215
Fig. 4. Pleurotoma ( Leiccosyrmx) pedroana, sp. nov. Lower San Pedro series, Deadman
Island. Type specimen. Longitude 17 mm.; X3. 202
Fig. 5. Mangilia kooveri, sp. nov. Upper San Pedro series, San Pedro. Type specimen.
Longitude 11 mm.; X3. 212
Fig. 6. Act(Z07i ( Rictaxis) puncloccelaia Carpenter. Upper San Pedro series, San Pedro.
Longitude 5.9 mm.; X3. 189
Fig. 7. Mangilia ( Taranis) sfrongi, sp. nov. Lower San Pedro series, Deadman Island.
Type specimen. Longitude 12 mm.; X3-5. 215
Fig. 8. Columbella ( Anackis) mi7iima, s]i. nov. Upper San Pedro series, San Pedro. Type
specimen. Longitude 5.5 mm.; X3. 237
Fig. 9. Eulima hastata Sovverby. Upper San Pedro series, San Pedro. Longitude
ID mm.; X3-4- 268
Fig. ID. Mangilia (Cythara) bratitieri, sp. nov. Lower San Pedro series, Deadman Island.
Type specimen. Longitude 10 mm.; X3.2. 211
Fig. II. Ocinebra hirida vax. cancellina Philippi. Upper San Pedro series, San Pedro.
Longitude 21 mm.; X2. 257
Fig. 12. Eulima 7>ticans Carpenter. Lower San Pedro series, Deadman Island. Longi-
tutle 12 mm.; X3-5. 269
Fig. 13. Pla7iorbis tu77iidus Pfeiffer. Upper San Pedro series, San Pedro. Maximum
diameter 12.7 mm.; X3. 195
Fig. 14. Pla/iorbis vermicularis GouLD. Upper San Pedro series, San Pedro. Maximum
diameter 1 1.5 mm.; X3- I95
Fig. 15. Euli//ia falcala Carpenter. Lower San Pedro series, Deadman Island. Longi-
tude 7 mm.; X3. 268
Fig. 16. Eupletira 77iuricifor77iis Broderip. Upper San Pedro series, San Pedro. Longi-
tude 33 mm. ; natural size. 248
Fig. 17. Scala bellastriata CKlLVE.TflTR'R.. Figure of living shell from .San Pedro. Longitude
18 mm.; X2. 263
Memoirs CalAcad. Sci. Ydl. hi.
[ArndldJ Elate IX.
PHcm-iJiH BBrrrcri k key. sj".
382 CALIFORNIA ACADEMY OF SCIENCES.
EXPLANATION OF PLATE X.
Pleurotoma ( Borsonia) hooveri, sp. nov. Lower San Pedro series, Deadman
Island. Type specimen. 12.7 mm.; X3. 201
Phorciis pidligo Martyn. Upper San Pedro series, Crawfish George's. Speci-
men slightly tilted back. Altitude 17.5 mm.; natural size. 328
Tornatina culcitella Gould. Lower San Pedro series, Deadman Island. Longitude
1 1 mm. ; X3-2. 190
Columbella solidula var. precursor, var. nov. Upper San Pedro series, San Pedro.
Tyi^e specimen. Longitude 14.4 mm.; XS-S- 236
Tornatina cerealis Gould. Lower San Pedro series, San Pedro. Longitude
4.5 mm.; X5-5- 189
Actizon (raskii SlRhRT^iS. Upper San Pedro series, San Pedro. Longitude 14 mm.;
X3- 188
Columbella ( Astyris) iuberosa Carpenter. Upper San Pedro series, San Pedro.
Longitude 6.5 mm. ; X3. 240
Columbella (Astyris) gausapata Gould. Upper San Pedro series, San Pedro.
Longitude 10 mm.; X3- 239
Columbella (Astyris) califotniana Gaskoin. Lower San Pedro series, Deadman
Island. Longitude 10 mm.; X3. 238
Columbella (Astyris) gausapata var. carinata Hinds. Upper San Pedro series,
San Pedro Longitude 7.7 mm. ; X3- 240
Tornatina eximia Baird. Pliocene, Deadman Island. Longitude 12.5 mm.; X3- 190
Polynices ( Neverita) recbiziana Petit. Upper San Pedro series, San Pedro.
Typical shape. Altitude 17.5 mm.; natural size. 314
Natica (Cryptonatica) clausa Broderip & SowERBY. Pliocene, Deadman Island.
Shouldered variety. Altitude 26 mm.; natural size. 313
Polynices ( Lunatia) Icwisii GouLD. Upper San Pedro series, San Pedro. Lon-
gitude 75 mm. ; X0.66. ■ 315
Margarita pupilla G0VI.U. Pliocene, Deadman Island. Altitude 7.5 mm.; X3- 333
Delphinoidea coronadocnsis, sp. nov. Pleistocene, Spanish Bight, San Diego.
Type specimen, view from above. Maximum diam. 2 mm.; XS- 320
Same specimen viewed from in front; XS- 320
Cylichna alba Brown. Lower San Pedro series, Deadman Island. Longitude
12 mm. ; X 1.5. 192
Fig. 19. Chlorostonia montereyi Kiener. Upper San Pedro series, Crawfish George's.
Specimen slightly tilted back. Altitude 28 mm. ; natural size. 326
Fig.
I.
Fig.
2.
Fig.
3-
Fig.
4-
Fig.
5-
Fig.
6.
Fig.
7-
Fig.
8.
Fig.
9-
Fig.
10.
Fig.
1 1.
Fig.
12.
Fig.
13-
Fig.
14.
Fig.
15-
Fig.
16.
Fig.
17-
Fig.
18.
Memoirs Cal.Acad.5ci.Vdl. hi
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384 CALIFORNIA ACADEMY OF SCIENCES.
EXPLANATION OF PLATE XI.
Fig. I. Peden ( Plagiodenmm) newsomi. sp. nov. Upper San Pedro series, Los Cerritos.
Type specimen, left valve. Altitude 26 mm. ; xi-4- 113
Fig. \a. Same specimen. Outline, showing convexity of valve. X1.4. 113
Fig. 2. Pecten ( Chlamvs) hericeus Gould. Pliocene, Deadman Island. Exterior of left
valve. Altitude 50 mm.; natural size. no
Fig. 3. Peden ( Plagiodenium) ventricosus SowERBY. Upper San Pedro series, San Pedro.
Exterior of left valve. Altitude 36 mm. ; x i-3. 1 14
Fig. 3a. Same specimen. Outline, showing convexity of valve; XI.3. 114
Fig. 4. Pecteji (Chlamys) hastatus Sovverbv. Pliocene, Deadman Island. Left valve,
exterior view. Altitude 38 mm.; X1.3. 109
Fig. i,a. Same specimen. Outline, showing convexity of valve; XI.3. 109
Fig. 5. Peden (Chlamys) hericeus var. strategj/s Dall. Lower San Pedro series. Dead-
man Island. Exterior of right valve. Altitude 21 mm. ; Xi-3- no
Fig. 6. Peden ( P/agiodenutniJ veji/n'cosus SowERBV. Upper San Pedro series, San Pedro.
Exterior of left valve. Altitude 56 mm.; natural size. 114
Fig. 6a. Same specimen. Outline, showing convexity of valve; natural size. 114
Memoirs LalAcad. Sli . Vol. in.
[ArndidJ Plate XI.
1 «
6 a
pHnra - um BRirroK r hey, s f.
386 CALIFOENIA ACADEMY OF SCIENCES.
EXPLANATION OF PLATE XIL
Fig. I. Pecle7i ( Pecfc7i) denfahis SowEV.Ti\. Living shell from Gulf of California. Exterior
of left or flat valve. Altitude 58 mm.; natural size. 104
Fig. la. Same specimen. Outline, showing convexity of right valve; natural size. 104
Fig. 2. Pecten (Chlamys) laliauritus Conrad. Upper San Pedro series, San Pedro.
E.xterior of left valve. Altitude 23 mm.; xi 3. m
Fig. 2a. Same specimen. Outline, showing convexity of same valve; XI.3. m
Fig. 3. Pecten (Pecten) stcarnsii Dall. Pliocene, San Diego. Exterior of left or flat
valve. Altitude 65.5 mm.; natural .'^ize. 106
Fig. 4. Pecten (Chlamys) taliauriliis vs.r. nio>iot!wen's 'Coi^RAV. Upper San Pedro series,
San Pedro. Exterior of left valve. Altitude 20.5 mm. ; xi-3- 112
Fig. 4a. Same specimen. Outline, showing convexity of same valve; XI.3. 112
Fig. 5. Pecten (Pecten) diegcnsis Dall. Living shell, Monterey. Outline, showing con-
vexity of right valve (which is the same as the convexity of the right valve of
P. stearnsii'). Altitude 72 mm.; natural size. 106
Fig. 6. Pecten ( Chlamys) jordani, sp. nov. Pliocene, Deadman Island. Type specimen,
exterior of right valve. Altitude 51 mm. ; X0.9. iii
Fig. 7. Same specimen, exterior of left valve; xo.g. 11 1
Fig. 8. Pecten (Chlamys) taliauritus var. fragilis, var. nov. Upper San Pedro series, San
Pedro. Type specimen, exterior of right valve. Altitude 25 mm. ; Xi-3. H2
Memoirs CjlAcaj]. 5ci. Ydljii.
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388 CALIFORNIA ACADEMY OF SCIENCES.
Fig.
r.
Fig.
2.
Fig.
3-
Fig.
4-
Fig.
5-
Fig.
6.
Fig.
7-
Fig.
8.
Fig.
9-
EXPLANATION OF PLATE XIIL
Cooperella subdiaphana Carpenter. Lower San Pedro series, Deadman Island.
Interior, showing hinge. Longitude 12.5 mm.; XS- i53
Callista subdiaphana var. pedroana, var. nov. Lower San Pedro series, Deadman
Island. Type specimen. Longitude 33 mm.; xo.8. 144
Aligeva cerritensis, sp. nov. Upper San Pedro series, Los Cerritos. Type speci-
men, view of interior. Longitude 10.9 mm.; X3. 138
Callista subdiaphana Carpenter. Pliocene, Deadman Island. Longitude 45 mm.;
XO.S. 144
Psephis laJitilla GoV'LD. Lower San Pedro series, Deadman Island. View of inte-
rior. Longitude 6 mm. ; X4. 133
Pecten ( Paiinopccten) caurinus Gould. Pliocene, Deadman Island. Exterior of
left valve. Altitude 122 mm.; xo.8. 107
Tellina ( Moerella) sahnonea Carpenter. Lower San Pedro series, Deadman
Island. Interior of right valve. Longitude 14 mm. ; X3.3. 157
Donax lavigata Deshaves. Upper San Pedro series, San Pedro. Interior view.
Longitude 21 mm.; X2.5. 170
Donax californica Conrad. Lower San Pedro series, Deadman Island. Interior
view. Longitude 17 mm.; X2.5. 170
Memdirs Cal Acad. 5ci . Vol. in.
[ArndldJ PlATE Ml.
.iim>*»^^*^^
puoTD-UTH BKrrroriitHEy.ST,
390 CALIFORNIA ACADEMY OF SCIENCES.
EXPLANATION OF PLATE XIV.
Fig. I. Vetius (Chione) succincla Valenciennes. Upper San Pedro series, San Pedro.
Exterior of right valve. Longitude 54 mm.; natural size. 149
Fig. 2. Venus ( Chione) fludifraga Sowerbv. Upper San Pedro series, S;»n Pedro. E.x-
terior of right valve. Longitude 25 mm.; xi-?- I47
Fig. 3. Vemts (CAwne) negleda Sowerby. Upper San Pedro series, San fedro. Lon-
gitude 30 mm.; X2.2. 148
Fig. 4. Tapes staminea Conrad. Upper San Pedro series, San Pedro. Longitude 50 mm.;
natural size. 150
Fig. 5. Tapes lacineata Carpenter. Upper San Pedro series, Los Cerritos, Longitude
10 mm.; x i.i- 150
Fig. 6. Tapes tenerrima Carpenter. Upper San Pedro series, San Pedro. Longitude
84 mm.; natural size. 151
Memoir
VlJ L_Y-_i_..i ^r^x^.
All.
[AhndldJ Hate IN.
PHcro rinH-HHrrroK « bey. bt.
392
CALIFORNIA ACADEMY OF SCIENCES.
EXPLANATION OF PLATE XV.
Fig. I.
Fig.
la.
Fig-
2.
Fig.
3-
Fig.
4-
Fig.
a,a.
Fig.
5-
Fig.
6.
Fig.
7-
Fig.
8.
Fig.
9-
Semele puldira Sowerby. Upper San Pedro series, San Pedro. Longitude
15 mm. ; X3 3. 166
Same. Outline, showing convexity of valve; X3-3. 166
Tellina {Angu/us) buttotii D.\ll. Upper San Pedro series, San Pedro. Interior
view. Longitude 13.5 mm. ; X4.6. 157
Same as fig. 2. E.xterior view; X46. 157
Semele pulchra var. fitoiilereyi, var. nov. Lower San Pedro series, Deadman Island.
Longitude 14 mm.; X3.3. 166
Same. Outline, showing convexity of valve; X3.3. 166
Thyasira bisecta CoNRAD. Pliocene, Deadman Island. Longitude 74 mm. ;
XI. I. 135
Cardium {Ringicardmm) procerum Sowerby. Upper San Pedro series, San
Pedro. Exterior view. Longitude 73 mm.; natural size. 139
Tellina i^Angulus) idee Dall. Upper San Pedro series, Los Cerritos. Longitude
62 mm.; X0.7. 158
Tellina {Angnhis) bodegetisis Hinds. Upper San Pedro series, San Pedro.
Longitude 50 mm. ; natural size. 158
Tellina (Angvlus) rnbescens Hanley. Ufjper San Pedro series, San Pedro.
Longitude 42 mm.; natural size. 159
Memoirs Cal Acffl. 5ci . Ydl. hi
[Arndld] Plate TY
I a
PHOTO -UrHBBITTaN R REV. BF.
394 CALIFOENIA ACADEMY OF SCIENCES.
EXPLANATION OF PLATE XVL
Fig. I. Macoma indenlala Carpenter. Upper San Pedro series, Los Cerritos. Longitude
50 mm.; natural size. 161
Fig. 2. Macoma calcarea Gmelin. Lower San Pedro series, Deadman Island. Longitude
18 mm. ; X2.3. 161
Fig. 3. Macoma nasuta Conrad. Upper San Pedro series, San Pedro. Large, typical
specimen. Longitude 75 mm.; natural size. 163
Fig. 4. Macoma inquinaia Deshayes. Upper San Pedro series, San Pedro. Longitude
42 mm.: natural size. 162
Fig. 5. Macoma secta Conrad. Upper San Pedro series, San Pedro. Longitude 82 mm.;
natural size. 164
Fig. 6. Macoma yoldiformis Carpenter. Lower San Pedro series, Deadman Island.
Longitude 24 mm.; natural size. 165
Fig. 7. Ve)ius {C/iione) g7iidia Broderip & Sowerby. Upper San Pedro series, San
Pedro. Exterior of right valve. Longitude 96 mm.; natural size. 147
Memoirs L?LMm. Sci. Ydl. iii
[ArndldJ Plate XVI
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396 CALIFORNIA ACADEMY OF SCIENCES.
EXPLANATION OF PLATE XVIL
Fig. I. Tercbratalia hemphilli Dall. Pliocene, Santa Barbara. View of pedicle valve.
Longitude 57 mm. ; xo.6. 92
Fig. 2. Same. Lateral view of both valves; xo.6. 92
Fig. .3. Same. View of brachial valve; xo.6. 92
Fig. 4. Leda hamata Carpenter. Lower San Pedro series, Deadman Island. Longitude
9.5 mm.; X4-5- 97
Fig. 5. Leda iaphria Dall. Lower San Pedro series, Deadman Island. Longitude
9.6 mm.; X4. 98
Fig. 6. Leda vihmta var. prescursor, var. nov. Lower San Pedro series, Deadman Island.
Type specimen. Longitude 9 mm.; X5. 97
Fig. 7. Leda fossa Baird. Lower San Pedro series, Deadman Island. Longitude
13.5 mm.; x3-2. 96
Fig. 8. Mytilimeria nuttalli Conrad. Lower San Pedro series, Deadman Island. Altitude
17 mm. ; x 1.4. 126
Fig. 9. Terebratalia smilhi, sp. nov. Pliocene, Deadman Island. Type specimen. Alti-
tude 50 mm. ; natural size. 93
Fig. 10. Verdcordia tiovemcoslata Adams & Reeve. Lower San Pedro series, Deadman
Island. Longitudes mm- 1 X4.5. 126
Fig. II. Corbiila luteola Carpenter. Lower San Pedro series, Deadman Island. Longi-
tude 8 mm.; X3. 181
Fig. 12. Bornia retifera Dall. Lower San Pedro series, Deadman Island. Interior view,
showing hinge. Longitude 7.5 mm.; X4. 136
Fig. 13. Yoldia scissiirata Dall. Lower San Pedro series, Deadman Island. Longitude
12.7 mm.; X4. 99
Memdirs Cal.Acad. Sci. VDL.in.
[ArndldJ Piate XVIL
10
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PHDTD -UTH BHTrraK It HEY. GT,
398 CALIFOKNIA ACADEMY OF SCIENCES
EXPLANATION OF PLATE XVIIL
Fig. I. Kellia suborbiailaris Montagu. Lower San Pedro series, Deadman Island.
Interior view of left valve. Longitude 8 mm. ; X4-3. 137
Same specimen. Outline, showing convexity of valve; X4.3. 137
Pandora { Ke7uierlia) bicarmata Carpenter. Lower San Pedro series, Deadman
Island. View of imperfect left valve. Longitude 14 mm. ; X3. 123
Pandora {Kennoiia) Jilosa Carpenter. Lower San Pedro series, Deadman Island.
Left valve. Longitude 15 mm.; X3. 124
Area lahiata Sowerby. Upper San Pedro series, San Pedro. Longitude 28 mm.;
XI. 3. lOI
Diplodonta serricata Reeve. Upper San Pedro series, San Pedro. I^ongitude
10.2 mm.; x3-3- '34
Same. Outline, showing convexity of valve; X3.3. 134
Nttcula suprasiriata Carpenter. Upper San Pedro series, Los Cerritos. Longi-
tude 7 mm.; X4.7- 96
Fig. 7. Kellia laperousii Deshayes. Lower San Pedro series, Deadman Island. Interior
view. Longitude 23 mm. ; X2. 137
Same. Outline, showing convexity of valve; X2. 137
Diplodonta orbella Gould. Lower San Pedro series, Deadman Island. Longitude
9.2 mm.; X3.3. I34
Same. Outline, showing convexity of valve; X3.3. 134
Glycymeris barbamisis Conrad. Upper San Pedro series, San Pedro. View of
interior. Longitude 25 mm. ; xi-3- 100
Glycymeris septcntrionalis Middendorff. Upper San Pedro series, San Pedro.
View of interior. Longitude 22 mm. ; xi-3. loi
Ne^ra pec f inula CKKPKtiTKV.. Lower San Pedro series, Deadman Island. Imper-
fect valve. Longitude 6.5 mm. ; X5.4. tSi
Astarte {Crassinella) branneri sp. nov. Upper San Pedro series, Los Cerritos.
Type specimen, interior view. Longitude 11. 2 mm. ; X2.7. 127
Fig.
Fig.
\a.
2.
Fig.
3-
Fig.
4-
Fig-
5-
Fig.
Fig.
5«-
6.
Fig.
7«-
Fig.
8.
Fig.
8a.
Fig.
9-
Fig-
10.
Fig.
II.
Fig.
12.
Memoirs Cal Acad. Sci . Vdl. hi.
[Ah;i._
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PHOTD-UTH BfirrrCKKHEV, BT
400 CALIFORNIA ACADEMY OF SCIENCES.
EXPLANATION OF PLATE XIX.
Fig. I. Madra {Spisu/a) falcata Gould. Upper San Pedro series, San Pedro. Interior
of left valve. Longitude 47 mm.; natural size. 176
Fig. 2. A/adra californica Conrad. Upper San Pedro series, San Pedro. Interior of left
valve. Longitude 39 mm. ; natural size. 174
Fig. 3. Madra hemphilli Dall. Upper San Pedro series, San Pedro. Interior of right
valve. Longitude 124 mm; natural size. 175
Fig. 4. Madra exoleta Gray. Upper San Pedro series, San Pedro. Interior view, right
valve. Longitude 57 mm.; natural size. 175
Fig. 5. Madra {Spisula) catilliformis Conrad. Upper San Pedro series, San Pedro. In-
terior of right valve. Longitude 125 mm.; natural size. 176
Memoirs Cal.Acad. Sci. Ydl.iii.
[ArndldJ Plate XIX
FKDTa -mH,HBJTTaK. * KEY. S F.
402 CALIFOENIA ACADEMY OF SCIENCES.
EXPLANATION OF PLATE XX.
Cardium {Lavicardium) elatum SowERBY. Upper San Pedro series, San Pedro. Exterior
of left valve. Altitude 167 mm.; natural size. 141
Memdirs Cal-Acad. Sci. Vdl.hi,
[Arndld] Plate XX.
PHDXD -TJTH HRTTTDK R HET. ST,
404 CALIFORNIA ACADEMY OF SCIENCES.
EXPLANATION OF PLATE XXL
Fig. I. Pecten bcllus Conrad. Pliocene, Santa Barbara. Left valve of Gabb's type speci-
men of Janira bella (No. 960, Collection Academy of Natural Sciences, Phila-
delphia). Altitude 80 mm., slightly enlarged. 103
Fig. 2. Same. Right valve. 103
Memoirs CAL/^rAD.Sci.VDLiii.
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Memoirs Cal Acad. 5ci Vol hi.
[Arnold] Plate XXV.
Figure a. San Pedro. — North end of Deadman Island, looking east, showing unconformity between
Pliocene and lower San Pedro (Pleistocene) strata. (See Diagram B, Plate XXII, for explanation.)
Photograph by R. Arnold.
Figure b. San Pedro,— East point of Deadman Island, looking north, showing unconrormity between
Pliocene and lower San Pedro (Pleistocene) strata.
Photograph by R. Arnold.
Memoirs Cal Acad. 5ci. Vol. hi.
[Arndld] Vlkte XXVI.
Figure a. San Pedro. — San Pedro bluff, looking southwest toward the San Pedro valley, showing lower
and upper San Pedro (Pleistocene) strata. (See Diagram D, Plate XXII, for explanation.)
Photograph by R. Arnold.
Figure b. San Pedro.— San Pedro bluff north of valley, lool<lng west, showing unconformity between
lower and upper San Pedro (Pleistocene) deposits. (See Diagram D, Plate XXII, for explanation.)
Photograph by Dr. H. W, Fairbanks.
iMemdirsCal Acad. Sci.Ydl III.
[Arnold] Piatc XXV^II
Figure a. San Pedro.— North end of the San Pedro bluff, looking northwest, showing fossiliferous
layers near top. Photograph by R. Arnold.
Figure b. San Pearo.— North end of the San Pedro bluff, looking southwest, showing fossiliferous
layers at the bottom. Photograph by R. Arnold.
MemdirsCalAcad.Sci Vgliii.
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Figure a. San Pedro. — Specimen of tlie fossiiiferous sand from the lower San Pedro deposits, San
Pedro bluff, north of valley. Olivella intorta is the dominating species.
Photograph by R. Arnold.
Figure b, San Pedro.— SpecimSn of the fossiiiferous lower San Pedro sandstone from Deadman
Island. Photograph by R. Arnold.
MemdirsCal Acad. Sci.Vdl. III.
[arndld] PiATE mi
Figure a. Long Beach.— Bluff at Alamitos Beach, looking east, showing horizontal upper San Pedro
(Pleistocene) strata. Photograph by R. Arnold.
••f
Figure b. Long Beach.— Typical section of the upper San Pedro (Pleistocene) bluff east of Long
Beach. (Lowest visible layer composed of fossil shells). Photograph by R. Arnold.
Memdirs Cal Acad. 5ci Vol, in.
[ArndldJ Plate XXX.
--■'■^^m
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Figure a. San Pedro. — South end of the lowest San Pedro terrace, looking northeast from Crawfish
George's toward Timm's Point, showing the contorted Miocene shales overlain by the thin horizontal upper
San Pedro (Pleistocene) layer. Photograph by R. Arnold.
Figure b. Port Harford. — Railroad cut at Fossil Point, looking south, showing Indian kitchen-midden
six feet thick and full of shells overlying the Pleistocene deposit of brecciated shale.
Photograph by R. Arnold.
Memoirs C^Acad. Sci. Volie.
[AhNDLdJ PlATE IXXI.
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Figure a. Pismo. — Section of sea-cliff three miles nortlnwest of Pismo, sinowing IVliocene shales on
right, overlain unconformably by San Pablo (IVIiddle Neocene) sandstone on left, the whole capped by
horizontal Pleistocene deposits of brecciated shale. Photograph by R. Arnold.
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Figure b. Santa Barbara. — Bluff just west of the bath-house, showing alternating hard and soft layers
of the lower San Pedro (Pleistocene) sandstone. Photograph by R. Arnold.
Memoirs Cal Acad. Sci . Vol. hi.
[Arndld] Piaie XXXII.
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Figure a. Santa Barbara.— Portion of bluff west of Rocl<y Point, showing asphaitum-impregnated
Pleistocene gravels resting on the Miocene shales. Photograph by R. Arnold.
Figure b. Santa Barbara. — Bluff west of Rocky Point, showing the Pleistocene sands and gravels
resting on the Miocene shales. Photograph by R. Arnold.
Memdirs CalAcad. Sci Vdl.iii.
[Arndld] Piate XXXIII.
Figure a. Ventura. — West side of the Ojai Valley, looking west from the boulevard, showing two of
the three wave-cut terraces in Pleistocene sediments. Photograph by R. Arnold.
Figure b. Ventura. — Hills north of Ventura composed of Pleistocene sediments, looking northeast.
The old irrigating ditch is seen about half way up the hill. Photograph by R. Arnold.
Memoirs Cal Acad. Sci . Ydl. III.
\'-:^"^zr' '.m ,.
[Arndld] Plate XXXIV
Figure a. Ventura. — Side of ravine above the Bariov/ ranch house, looking west, showing fossiliferous
upper San Pedro (Pleistocene) beds at an elevation of over six hundred feet above sea-level, dipping at an
angle of over 40°. Photograph by R. Arnold.
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Figure b. San Diego. — Blutt at La Jolla capped by Pleistocene deposit of gravel and sand.
Photograph by F. L. Parl<.
Memdirs Cal Acad. Sci. Vol m.
[AhnoldJ Plate XXXV.
Figure a. San Diego. — Bluff at foot of Twenty-sixth street, looking north, showing the fossiliferous
upper San Pedro (Pleistocene) deposits in the lower half of the bluff. The Anomia limatula bed is at the
very base of the bluff and forms the reefs at the right of the picture.
Photograph by R. Arnold.
Figure b. San Diego. — Small section of the sea-cliff at Pacific Beach, showing Pecten expansus and
Opalia varicostata in the matrix of the San Diego formation (Pliocene).
Photograph by R. Arnold.
Memoirs Cal Acad. Sci . Vol. hi.
[Arnold] Plaie XXXVl.
Figure a. San Diego.— Sea-cliff at Pacific Beach, lool<ing north, showing the base of the slightly tilted
sandstone of the San Diego formation (Pliocene), resting on massive gravels and conglomerates.
Photograph by R. Arnold.
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Figure b. San Diego.— Sea-clift at Pacific Beach, looking north from a point one-half mile north of
Ocean Front, showing slightly tilted sandstones of the San Diego (Pliocene) formation capped by horizontal
upper San Pedro (Pleistocene) gravels. Photograph by R. Arnold.
Memoirs Cal Acad. 5 CI. Vdl. III.
[ArhdldJ Plate XX/yjI,
Figure a. San Diego.— Bluff and beach at Spanish Bight, looking north, showing the very fossiliferous
layer at the base of the bluff which also forms the beach at this point.
Photograph by R. Arnold.
Figure b. San Diego, — A closer view of the beach at Spanish Bight. Most of the shells seen in this
picture are In place in the hard Pleistocene sand layer which forms the beach at this point.
Photograph by R. Arnold.
Index to Volume III,
New generic, specific and subspecific names in heavy-faced tyi^e; synonyms in italics.
AciLA 72, 95
castrensis 72, 95, 138
lyalli 95
Acmsea 84, 317
tlepicta 25, 39, 84, 317
insessa 15, 19, 22, 23, 25, 27, 31, 39, 52, 60, 84, 318
instabilis 25, 39, 84, 318
mitra 25, 39, 84, 197, 317, 318
paleacea 25, 39, 84, 317, 319
pelta 19, 27, 31, 33, 39, 55, 60, 84, 319
spectrum 19, 23, 27, 33, 39, 84, 320
AcmiBidaj 84, 317
Actc-Bou 77, 188
punctocojlata 19, 22, 27
(Eictaxis) punctoccelata 39, 55, 60, 189
traskii 27, 39, 60, 77, 188, 189
Act!eonid» 77, 188
Acus 78, 198
simplex 78, 198
Adesmacea 77, 183
Admete 79, 219
gracilior 19, 39, 52, 79, 219
yiridula 219
^sopus 80, 237
chrysalloidea 80, 237, 238
japonious 237
oldroydi 80, 238
Akera culcitella 190
Aleles sqtiamigerus 299
Aligeua 74, 138
cerritensis 30, 35, 74, 138
striata 138
Amaltheidaj 83, 311
Amaura 82, 282
Candida 282
nuciformis var. avellana 82, 283
pupiformis 82, 283
Amauropsis 282
Amiantis 59, 75, 145
callosa 27, 30, 35, 57, 59, 60, 75, 145
Amphidesma decisa 165
pulchra 166
Amphissa 80, 241
bicolor 242
corrugata 15, 19, 25, 27, 31, 39, 52, 80, 237, 241, 242
Inberosa 240
ventricosa 19, 39, 80, 242
versicolor 19, 23, 25, 27, 31, 39, 60, 80, 242
Amusium caiirinum 107
Amycln carinala 240
chrysalloidea 237
gausapata 239
Amycla tuhcrosa 240
Anaohis 80, 237
minima 80, 237
rugosa 237
Anatinacea 73, 121
Angulus 75, 157
bodegensis 75, 158
bnttoui 18, 21, 23, 25, 27, 30, 35, 55, 75, 157, 158
idiB 75, 158
modcslus 157
var. obtusus 157
rubescens 75, 159
Anomalodesmacea 73, 121
Auomia 59, 73, 117
ephippium 117
lampe 18, 21, 25, 27, 30, 32, 35, 55, 56, 60, 73,
117, 118
limatula 59, 60, 73, 117, 118
macroschisma 116
Anomiacea 73, 116
Anomiida) 73, 116
Authozoa 46, 71, 86
Area 16, 72, 101, 102
glycymeris 100
labiata 27, 35, 67, 72, 101
norei 101
nucleus 95
sulcicosta 57
Arcacea 72, 100
Arcidaa 72, 100
Arcinas 72, 101
Arcopagia medialis 160
Artemis ponderosa 146
Arthropoda 85, 344
Arthropomata 71, 92
Astartacea 73, 127
Astarte 73, 127
branneri 27, 30, 60
(Crassinella) branneri 35, 127
compacta 127
obliqua 127
semisulcata 127
Astartidaj 73, 127
Astralium incequale 321
Astyris 80, 238
californiana 80, 238
chrysalloidea 237
clausilioeforme 238
gausapata 56, 80, 238, 239, 240
var. cavinata 80, 240
tnherosa 80, 240
Auriculidae 78, 196
406
CALIFOENIA ACADEMY OF SCIENCES.
Axinea harbarensia 100
intermedia 100
BALAKIDiE 85, 344
Balanus 85, 344
ooncavus 22, 24, 25, 28, 31, 32, 47, 52, 55, 60,
85, 344
cylindraceus var. concavuK 344
Bela 78, 209, 210
fidicula 15, 19, 25, 39, 52, 55, 78, 209, 210
sanctse-monicae 19, 39, 56, 78, 210
sculplurata 214
Bittium 82, 291
asperum 15, 17, 19, 25, 27, 39, 52, 55, 56, 60,
82, 291, 293, 294
californicnm 19, 39, 82, 291
(Elachhta) californicnm 291
filosum 19, 22, 25, 27, 39, 82, 292, 293, 294
orthochila 295
quadriHlatum 19, 22, 23, 25, 28, 31, 39, 52, 82,
292, 293, 294
reticulatum 291
rugatum 19, 22, 23, 25, 28, 31, 39, 82, 290, 295
(Styliferiua) teuuisculpta 296
williamsoni 28, 39, 60, 82, 292, 295
Boreotrophou 80, 249
cerritensis 80, 249
gracilis 80, 250
luulticostatus 80, 251
orpheus var. praecursor 80, 250, 251, 253
pedroana 80, 251
scalariformis 80, 252
stuarti 80, 252
teuuisculptus 80, 253
triaugulatns 80, 254
Bornia 74, 136
corbiiloides 136
retifera 18, 35, 74, 136
Borsonia 78, 200
Ijartsclii 78, 200, 207
dalU 78, 200, 201
hooveri 78, 200, 201
Brachiopoda 15, 46, 71, 92
Brachyura 85, 345
Bryozoa 46, 52, 71, 92
Bucciuidfe 79, 227
Buccinum corrui/atum 241
fossatvm 232
Bulla 77, 193
adamnii 193
ampulla 193
(Tornatina) cerealis 189
(Akera) culcitella 190
uebulosa 33, 193
punctata 193
puuctulata 23, 25, 28, 31, 39, 67, 77, 193
quoyi 28, 39, 77, 193
virescens 194
Bullidaj 77, 193
Caddlus 77, 187
fusiformis 187
nitentior 19, 47, 55, 60, 77, 187
subfusiformis 187
Cajcidffi 82, 297
Cajcum 83, 297
californicum 19, 22, 28, 31, 39, 83, 297, 298
cooperi 297
coruuoides 297
crebriclnctum 19, 22, 25, 28, 31, 39, 83, 297, 298
maguum 19, 22, 39, 83, 298
Calliostoma 84, 329
anuulatum 28, 39, 84, 329
caualiculatum 15, 19, 22, 23, 25, 28, 31, 33, 39,
60, 84, 329
costatum 19, 22, 25, 28, 31, 39, 60, 84, 330
gemmulatum 25, 28. 31, 39, 52, 60, 84, 330
tricolor 15, 22, 23, 25, 28, 31, 39, 60, 84, 331
zizyphinum 329
Calliostomai 328
Callista 74, 143
(Amiantis) callosa 145
uewcombiaua 35, 59, 60, 74, 143
subdiaphana 15, 17, 35, 74, 144, 145
var. pedroana 18, 35, 74, 144
Calyptrcea echinus 308
fastigiata 307
hy.strix 308
mamiUaris 307
spinosa 306
CalyplraaidiB 83, 306
Cancellaria 79, 217
cancellata 217
cassidiformis 218
cooperi 28, 39, 79, 217
(Nai-07ia] cooperi 217
crawfordiana 28, 39, 217
gracilior 219
tritonidea 28, 39, 55, 67, 78, 218
vetusta 218
Cancellariidaj 79, 217
Cancer 60, 85, 345
breweri 20, 47, 85, 345
magister 345
Cancrini 85, 345
Cancroidea 85, 345
Capulus lumens 313
Cardiaeea 74, 138
Cardiida) 74, 1.38, 141
Cardita monilicosta 128
occidentalis 128
suhtenta 128
ventricosa 128
CarditidfB 73, 128
Carditacea 7.3, 128
Cardium 74, 138
californicum 140
californiense 68
centifilosum 142
corbis 18, 21, 23, 25, 27, 30, 35, 52, 68, 140
ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO.
407
Cardium (Cerastoderma) corbis 140
edule 140
elatum 27, 30, 35, 67, 141
(Laivicardium) elatum 141
hillauiim 142
isocardia 138
luleolabrum 139
modestum var. centiJilo>ium 142
norvegioum 140
nuUalli 140
panamense 56, 139
proceram IS, 27, .30, 32, 35, 56, 59, 60, 139
(Riugicardium) procerum 139
quadrigeuarium 27, 30, .32, 35, 60
(Traohycardium) quadrigenarium 139
ringeus 139
substriatum 141
(Laivicardium) substriatum 141
Caryophyllia 71, 86
aruoldi 46, 71, 86, 87, 88
californica 46, 71, 87, 88
pedroensis 46, 71, 87, 88
Cerastoderma 74, 140
corbis 74, 140
Cerithiacea 82, 290
Cerithidea 82, 296
califoruica 15, 19, 22, 23, 25, 28, 31, 33, 40, 60,
82, 296, 297
decollatum 296
sac rata 297
CerithiidiB 82, 291
CerithiopsidiB 82, 290
Cerilhiopds asshnilala 290
Cerilhium caU/ornkum 296
filostim 292
(Potamis) sacratum 296
Cerosloma folialum 245
nullalli 245
Chama 74, 130
exogyra 27, 30, 35, 74, 130
lazarus 130
pelluoida 15, 18, 23, 25, 27, .30, 35, 74, 130
sp'moaa yax. ptllucida 130
Chamacea 73, 130
Chamida) 130
Chemnilzia crcbrifilata 276
(jibbosa 279
muricata 270
similis 270
subcuspidata 277
tenuicula lib
torquata 271
var. stylina 272
tridenlata 273
var. auranlia 272
Chicoreus 80, 243
leeauus 80, 243
trialatus 80, 243
Chioue 75, 147
brevilineata 149
Chione callosa 147
calif orniensis 149
ducfifraija 60, 75, 147
gvidia 75, 147
neglecta 75, 148
nullalli 149
sitnillwia 32, 56, 60, 75, 148
succincta 33, 55, 56, 60, 75, 148, 149
Chiton amiculalus 342
californicus 342
muscosus 343
regularis 342
sitkensis 342
stelleri 342
(Cryptochilon) stelleri 342
Chitonidio 85, 342
Chlamys 72, 107, 109
hastatus 72, 109
hericeiis 72, 110
var. strategus 72, 110
jordani 72, 111
latiauritus 72, HI
var. fucicolus 112
var. fragiUs 72, 112
var. monotimeris 72, 112
opuntia 72, 113
Chlorostoma 84, 324
argyrostroma 324
aureotinctum 28, 40, 84, 324
brunuenm 15, 23, 25, 40, 50, 84, 324
fuuebrale 19, 22, 23, 25, 28, 31, 32, 33, 40, 55,
60, 84, 325
var. subapertum 19, 22, 23, 25, 28, 31,
40, 84, 325
gallina 23, 25, 28, 40, 60, 84, 326
marcidus 328
monterei/ensis 326
montereyi 15, 19, 23, 25, 28, 40, 60, 84, 325, 326,
328
pfeifferi 326
pulligo 328
subapertum 23
(Omphalius) viridulum var. ligulatum 19, 22,
23, 25, 28, 31, 40, 327
viridulus 327
Chorus SO, 247
belcheri 25, 28, 31, 40, 55, 80, 247
Chrysallida 82, 281, 283
communis 283
diegensis 82, 284
Chrysodomus 15, 40, 79, 227, 229
autiqua 227
dirus 229
rectirostris 15, 19, 25, 40, 79, 22S
tabulatus 15, 17, 19, 22, 40, 52, 55, 67, 79, 228
Cirripedia 85, 344
Clathurella 78, 210
canfieldii 211
conradiana 15, 19, 22, 28, 40, 52, 78, 210
Clavatula 210
408
CALIFORNIA ACADEMY OF SCIENCES.
dementia subdiaphana 144
Clidiophora 73, 124
claviculata 124
punctata 18, 27, 35, 60, 73, 124
Clypeastroida 71, 91
Clypidella 85, 339
bimaculata 19, 22, 28, 31, 40, 60, 85, 339
callomarginata 19, 22, 25, 28, 31, 40, 85, 339, 340
pustulata 339
Cojlenterata 71, 86
Columbella 80, 236
oaliforniaua 19, 22, 238, 239
(Astyris) californiana 40, 238
carinala 240
chrysalloidea 19, 22, 28, 237
(^Esopus) chrysalloidea 40, 60, 237
gausapata 15, 17, 19, 22, 23, 25, 28, 31, 33, 239,
240
var. carinata 15, 17, 19, 22, 23, 25, 28,
31, 32, 33, 239
(Astyris) gausapata 40, 52, 55, 60, 239
var. carinata 40, 52, 55, 60, 240
mercatoria 236
minima 28
(Auachis) minima 48, 237
oldroydi 19
(^sopus) oldroydi 40, 238
solidula 80, 236, 237
var. praecursor 28, 40, 236
tuberosa 19, 22, 23, 25, 28, 31, 239, 240
(Astyris) tuberosa 40, 52, 60, 240
Columbellidas 80, 236
Comliiella ( Amphissa) corrui/ata 241
Conchoccle bisecta 135
disjuncta 135
C'oncholepas antiqualus 312
Couidas 78, 199
Conus 78, 199
californicus 15, 17, 19, 22, 23, 25, 28, 31, 32, 33,
40, 60, 78, 197, 199
marmoreus 199
ravus 199
Cooperella 75, 153
subdiaphana 18, 35, 61, 75, 153
Cooperellidfe 75, 153
Coralliophila 81, 262
ne'ritoidea 262
nux 28, 40, 81, 262
Coralliophilinse 81, 262
Corbula 76, 180
gallica 180
luteola 15, 18, 21, 27, 30, 35, 61, 76, 181
Corbulidai 76, 180
Crassinella 73, 127
branneri 73, 127
Crepidula 83, 307
aculeata 19, 22, 28, 40, 68, S3, 308
adunca 19, 22, 24, 28, 31, 40, 52, 55, 56, 61, 83,
308, 311
cali/ornica 308
Crepidula convexa 308
dorsata 19, 25, 31, 40, 83, 309
excavata 57
explanata 310
grandis 24, 40, 58, 61, 68, 83, 309, 310
navicelloides 19, 22, 24, 25, 28, 31, 40, 52, 83, 310
nummaria 310
onyx 19, 22, 24, 28, 31, 40, 61, 83, 310, 311
var. rvgosa 311
peruviana 307
prajrupta 309
princeps 309
rostriformis 308
rugosa 19, 24, 25, 28, 31, 32, 33, 40, 50, 83, 311
Crucibulum 83, 306
axirkula var. spinosum 306
dumosum 306
rudis 306
spinosum 22, 23, 24, 25, 28, 31, 32, 33, 40, 56,
61, 83, 306
Crustacea 20, 22, 24, 25, 28, 31, 47, 85, 344
Crypla adunca 308
dorsata 309
Cryptochitou 85, 342
stelleri 15, 19, 40, 68, 85, 342
Cryptodon bisectus 135
flexuosus 135, 136
nuttalli 178
Cryptodontidaj 74, 135
Cryptomya 76, 179
califoruica 18, 21, 23, 25, 27, 30, 32, 33, 35, 55,
61, 76, 179, 180
ovalis 180
Cryptonatica 83, 313
clausa 83, 313
Ctenobranchiata 78, 198
Cumingia 76, 167
califoruica 15, 18, 21, 23, 25, 27, 35, 76, 167
mutica 167
similis 167
Cupulifera 92
Cyclas acutilineata 131
Cyclostrematidai 85, 335
Cylichua 77, 192
alba 19, 28, 41, 55, 61, 68, 77, 191, 192
arachis 192
cylindracea 67, 192
Cyprasa 82, 288
argus 288
spadicea 24, 41, 82, 288
Cyprajidai 82, 288
Gypricardia pedroana 155
Cyprina bisecta 135
Cythara 78, 211
branneri 19, 41. 52, 78, 211
Cytherea 142
callosa 145
crassatelloidcs 143
( Tivela) crassalelloides 143
( Trigonella) crassatelloidcs 143
ARNOLD — THE PALEONTOLOGY AND STKATIGEAPHY OF SAN PEDRO.
409
Cytherea erycina 143
gigantea 146
solidissima 143
slullorum 143
Daphnella 210
filosa 223
inter/ossa 213
Decapoda 85, 345
Delphinoidea 84, 320
cancellata 320
coronadoensis 61, 84, 320
Dendropoma lituella 299
DentaliidiB 77, 185
Dentalium 77, 185
elephautinum 185
hexagonum 19, 22, 24, 25, 28, 31, 32, 47, 55, 61,
68, 77, 185
indianorum 19, 22, 25, 47, 77, 186, 187
neohexaijovtim 185, 186
pretiosuin var. indianorum 186
pseudohexagonum 19, 28, 47, 61, 77, 186
semipolitum 24, 25, 28, 47, 77, 187
seniislriatum var. semipolitum 187
Diadematoida 71, 90
Diastoma 19, 41, 52, 82, 296
Dione augustiformis 144
nobilis 145
Diplodonta 74, 133
lupiuus 133
orbella IS, 25, 27, 35, 61, 74, 133, 134
serricata 27, 35, 61, 74, 134
Diplodontidffi 74, 133
Dispolma dumosa 306
Ditremata 78, 196
Docoglossa 84, 317
Dolichotoma 78, 202
carpenteriana 78, 202
cooperi 78, 203
tryouiaua 78, 203
DonacidiB 76, 169
Donax 76, 157, 169, 171
californica 18, 21, 27, 35, 76, 170, 171
californictis 170, 171
flexuosus 170
liBvigata 18, 21, 23, 25, 27, 30, 32, 33, 35, 55, 59,
61, 76, 170, 171
navicula 170
obesus 170
stuUorum 143
trunculus 169
Dosinia 16, 146
eallosa 145
discus 146
ponderosa 59, 61, 146
Dosinluaj 75, 146
Drillia 78, 204, 212
caucellata 19, 31, 41, 61, 78, 204, 205
hemphilli 19, 22, 28, 31, 41, 55, 61, 78, 204, 207
incisa 61, 78, 205
(62 )
Drillia inermis 19, 28, 31, 41, 55, 61, 68, 78, 204, 205, 206
var. penicillata 19, 22, 24, 25, 28, 31, 32,
33, 41, 55, 61, 205
johnsoni 28, 41, 78, 206
merriami 15, 19, 41, 78, 207
moesta 200
montereyensis 19, 41, 78, 207
pallida 207
penicillata 78, 205
perversa 208
pudica 28, 41, 78, 208
renaudi 78, 208
torosa 15, 17, 19, 22, 24, 25, 28, 31, 41, 78, 100,
207, 208, 209
Dunkeria laminata 277
ECHINARACHNlnS 71, 91
excenlriciis 20, 22, 24, 25, 28, 31, 46, 53, 55, 57,
58, 61, 71, 91
EchinometridfB 71, 90
Echinoidea 20, 22, 24, 25, 28, 31, 46, 71, 90
Echiuodermata 71, 90
Echinus piirpurattts 90
Elachista californicum 291
Elasmobranchii 85, 346
Emarginuliufe 85, 337
Eochitonia 85, 342
Epiphragmophora 77, 194
Erato 82, 289
columbella 28, 41, 82, 289
laevis 289
Eucrustacea 85, 344
Euechiuoidea 71, 90
Eulima 81, 268
falcata 19, 41, 81, 268, 269
hastata 19, 28, 41, 55, 61, 81, 268, 269
micaus 19, 22, 25, 28, 31, 41, 55, 61, 81, 268, 269
tortuosa 268
Eulimida) 81, 268
Eupleura 80, 248
caudata 248
muriciformis 19, 24, 28, 41, 61, 67, 80, 248, 249
var. curta 28, 41, 80, 249
var. pleistoceuensis 249
var. unispinosa 248, 249
Evalea 82, 281
cequisculpta 284
elegaus 281
gouldii 82, 282
stearnsii 82, 282
Fasciolariid^ 79, 224
Fissurella 85, 340
aspera 338, 340
crenulata 337
inceqtialis 338
var. pica 338
pica 338
picta 340
volcano 19, 22, 24, 25, 28, 31, 33, 41, 61, 85, 340
June 20, 1903.
410
CALIFORNIA ACADEMY OF SCIENCES.
Fissurellidaa 85, 337
Fissurellidcea bimaculata 339
callomarginata 340
Fissurellideinas 85, 337
Fissuridea 85, 337
aspera 19, 22, 24, 25, 28, 31, 41, 85, 338, 339
inajqualis 24, 28, 31, 32, 41, 85, 337, 338
murina 19, 24, 25, 28, 31, 41, 85, 339
Fossaridfe 83, 304
Fossarus 83, 304
costatus 304
(Isapis) feuestrata 304
Frenula Jeffrey si 93
FusiniB 79, 224
Fusus, 79, 224
ambustas 225, 226, 227
barbarensis 15, 17, 19, 24, 25, 28, 41, 79, 224,
225
cancellinus 257
corpulenlus 224
dupelithouarsi 224
Jidicula 209
geniculus 225
kobelli 226
luteopictus 19, 24, 25, 28, 31, 41, 79, 225
nicobaricus 224
oregonensis 286
robustus 19, 24, 25, 28, 41, 52, 79, 219, 224, 225,
226, 227
rugosus 19, 41, 79, 224, 225, 226, 227
acalariformis 252
Gadinia 78, 197
afra 197
radiata 197
(Rowellia) radiala 197
reticulata 41, 78, 197
var. radiata 197
Gadiniidaa 78, 197
Galerus 83, 307
chineusis 307
contorlus 307
mammillaris 19, 22, 25, 28, 41, 52, 83, 307
Gastropoda 15, 17, 19, 22, 23, 25, 27, 31, 33, 39, 77, 188
Gemminae 75, 152
Genota 78, 202
carpenteriana 202
Gibbula optabilis 332
parcipieta 333
Glottidia 71, 94
albida 52, 71, 94
Glycymeris 72, 100
barbarensis 23, 25, 27, 30, 35, 61, 72, 100, 101
estrellana 182
generosa 182
iutermedia 101
septentrioualis 23, 25, 27, 30, 32, 36, 72, 100, 101
Olyphis aspera 338
densiclathrata 339
var. murina 339
(rbjphis ineerjuaUs 338
Gj-mnoglossa 81, 268
Haliotid^ 68, 69, 85, 336
Haliotis 33, 49, 50, 68, 85, 336, 337
cracheroidii 3.3, 336
fulgeus 24, 34, 41, 61, 85, 336, 337
gigantea 336
rufesceus 336
sjilendtns 336
Hamiuea 77, 194
cymbifortnis 194
hydatis 194
virescens 28, 41, 77, 194
Helicidaj 77, 194
Helix 28, 77, 194
cuyana 194
(Epiphragmophora) 41, 195
Hinnites 72, 115
cortezi 115
crassus 115
giganteus 21, 23, 27, 30, 36, 72, 115
poulsoni 115
Hipponyx 83, 311, 312
antiquatus 15, 19, 41, 8.3, 102, 312, 313
cornucopias 311
cranioides 19, 22, 24, 31, 41, 61, 83, 312
mitrula 102, 312
tumens 19, 22, 24, 41, 61, 83, 312, 313
Hydrobiinaa 8.3, 305
Hygrophila 77, 195
IsAPis 83, 304
anomala 304
fenestrata 19, 22, 24, 25, 28, 42, 83, 304
Ischnochitou 85, 342
lougicymoa 342
regularis 28, 42, 85, 342
Ismenia jeffreysi 93
Isopleura 85, 342
Ivara 82, 285
terricula 19, 42, 82, 285
Janira bella 103, 104, 105
denlala 104, 105, 106
excavala 104
Jouanuetiua3 77, 184
Kellia 74, 136, 154
laperousii 15, 18, 21, 36, 61, 74, 136, 137
suborbicularis 18, 21, 36, 68, 74, 137
Kelliellidas 74, 138
Keuuerlia 73, 123
bicarinata 18, 36, 73, 123
Jilosa IS, 36, 7.3, 123, 124
Labiosa 76, 177
(Rit'ta) iindulata 177
Lacuna, 83, 302, 321
carinala 303
oompacta 19, 28, 31, 42, 52, 55, 61, 83, 302, 303
ARNOLD— THE PALEONTOLOGY AND STKATIGKAPHY OF SAN PEDRO.
411
Lacuna pallidula 302
porrecta 19, 22, 24, 25, 28, 31, 42, 83, 303
solidula 19, 28, 42, 61, 83, 303
var. compacta 302
LfBvieardium 74, 140
elatum 74, 141
substrlatum 18, 21, 23, 25, 27, 30, 33, 36, 61, 74,
141
Lamellaria 84, 317
depressa 317
perspicua 317
steaiusii 19, 42, 61, 84, 317
Lamellariidae 84, 317
Laucea 81, 272
aurantia 81, 272
elougatii 272
pentalopha 81, 274
tridentata 81, 273
Laquens 71, 93
californicus 93, 94
var. vancouverensis 93
jeffreysi 15, 46, 51, 52, 53, 71, 93
Lazaria 74, 129
pectunculus 129
subqiiadrata 18, 21, 25, 27, 36, 74, 129
Leda 57, 72, 96
calata 98
fossa 18, 36, 72, 96
hamata 18, 36, 61, 72, 97
miuuta var. prsecursor 18, 21, 36, 72, 97
pernula 96
taphria 15, 17, 18, 21, 23, 25, 27, 31, 32, 36, 61,
72, 98
Ledidre 72, 96
Lepas tintinnabulum 344
Leptonacea 74, 136
Leptonidae 74, 136
Leptonyx hacula 323
sanguinea 323
Leptothyra 84, 322, 323
bacula 19, 31, 42, 52, 84, 323, 324
oarpeuteri 19, 22, 25, 28, 42, 68, 84, 322, 323, 324
paucicostata, 19, 42, 52, 84, 323
sanijuinea 323
sangumeus 323
Leucosyriux 78, 202
pedroana 78, 202, 208
Lima 73, 115
dehiseens 18, 36, 116
(Maatellum) dehiseens 116
hians 115
orientalis 116
squamosa 115
Limidag 73, 115
Limna^idau 77, 195
Lingula albida 94
LingulidjB 71, 94
Linguliuffi 71, 94
Liocardium crueiilatum 141
elatum 141
Liocardium snbstrialum 141
Lioconcha ntwcombiana 143
Liotiidas 84, 320
Lithophaga 73, 121
plumula 73, 121
Lithophagus plumula 31, 36, 121
Littorina 83, 301
litorea 301
palula 301
pedroana 303
plauaxis 13, 19, 22, 28, 42, 83, 301
plena 302
scutulata 19, 22, 24, 25, 28, 31, 32, 42, 55, 61,
83, 301, 302
Littorinidffi 83, 301
Lucapina 85, 337
creuulata 31, 42, 85, 337
Lucapinella callomarginaia 340
LucinidiB 74, 131
Lucina 74, 131
acutiliueata 14, 15, 17, 18, 21, 23, 25, 27, 36, 52,
61, 65, 67, 68, 74, 131, 132
borealis 67, 131
californica 15, 18, 21, 23, 25, 27, 31, 32, 33, 36,
52, 56, 62, 74, 132
jamaicensis 131
nuttalli 18, 21, 23, 25, 27, 31, 32, 33, 36, 62, 74,
132
orbella 134
tenuisculpta 27, 36, 61, 74, 133, 134
teirica 131
Lucinacea 74, 131
Lunatia 84, 315
letoisii 32, 50, 57, 84, 315
Luponia spadicea 288
Lutraria canaliculata 177
capax 17S
maxima 178
(Cryptodon) nullalli 178
transmontana 177, 178
undulata 177
venlricosa 175
Lutrariiuas 76, 178
Lutricola alia 160
Lyonsia 73, 125
bracleata 125
californica 15, 18, 21, 23, 25, 27, 36, 73, 125
nilida 125
norvegica 125
Lyonsiidaa 73, 125
Mach^era patula 173
Macoma 52, 75, 160, 161, 169
calcarea 18, 36, 75, 161
edulis 68
expansa 161
indentata 27, 31, 36, 62, 75, 161, 163
iuquinata 15, 18, 23, 25, 27, 31, 33, 36, 48, 56,
62, 68, 75, 162, 163
kelseyi 161, 162, 163, 164
412
CALIFOENIA ACADEMY OF SCIENCES.
Macoma nasuta 18, 21, 23, 25, 27, 31, 32, 33, 36, 55,
57, 62, 68, 75, 162, 163, 164, 167
var. kelseyi 27, 31, 36, 62, 75, 164
pedroana 157
seota 18, 21, 23, 25, 27, 31, 32, 33, 36, 62, 68, 75,
163, 164
(Rexithosrus) secia var. edulis 164
tenera 160, 161
tersa 163
yoldiformis 18, 21, 36, 62, 75, 161, 163, 165
Macron 79, 230
kellettii 28, 42, 79, 230
lividus 42, 79, 230
Mactra 76, 164, 174
anatina 177
californica 27, 36, 59, 62, 76, 174, 175, 176
catilliformis 23, 25, 27, 31, 33, 55
(Spisula) catilliformis 36, 62, 176
exoleta 27, 36, 62, 67, 76, 175
falcata 18, 21, 23, 25, 27, 31, 33, 176
(Spisula) falcata 36, 62, 176
hemphilli 27, 36, 76, 175
maxima 178
plauulata 174
var. falcata 176
solida 175
stultomm 174
Mactracea 76, 174
Mactridas 76, 174
Mactrinaa 76, 174
Mcera salmonea 157
Malacostraca 85, 345
Maugilia 55, 78, 210, 211
angulata 10, 22, 25, 31, 42, 52, 55, 62, 78, 212
(Cythara) branneri 211
(Clathurella) couradiaua 210
hooveri 28, 42, 78, 212
interfossa 213
var. pedroana 19, 25, 42, 52, 79, 213
interlirata 19, 31, 42, 79, 213
oldroydi 19, 42, 79, 213, 214, 215
painei 19, 42, 79, 214
sculijturata 15, 42, 79, 214, 215
striosa 28, 31, 42, 62, 79, 215
(Taranis) strongi 215
variegata 212
Mangiliffi 214
Mantellum 73, 115
dehiseens 7.3, 116
Margarita 84, 332
calosloma 333
cidaris 3.34
heliciua 332
optabilis 332, 333
var. knechti 22, 23, 28, 42, 84, 332, 333
var. nodosa 19, 22, 42, 84, 332
parcipicta 84, 333
var. pedroana 19, 22, 24, 28, 31, 42, 84,
333
pupilla 42, 52, 84, 333
Margarita salmonea 333
Marginella 79, 221
globella 221
jewettii 19, 22, 24, 25, 28, 42, 79, 221
(Volvarina) varia 222
MargiuellidiB 79, 221
Megatebennus bimaculatus 339
Megerlia jeffreysi 93
MelampiiiiB 78, 196
Melampus 78, 196
Melampus luteus 196
olivaceus 19, 22, 24, 25, 28, 31, 42, 62, 78, 197
Melauia rufa 274
scalaris 277
Me.rcenaria perlaminosa 146
Meretrix callosa 145
Metis 75, 160
alta 18, 23, 25, 27, 31, 36, 62, 75, 160
Mitra 79, 222
episcopalis 222
maura 22, 24, 25, 28, 42, 79, 222
Mitridas 79, 222
Mitromorpha 79, 223
aspera 223, 224
filosa 19, 42, 79, 223, 224
gracilis 223
intermedia 19, 42, 52, 79, 223
Modelia striata 303
Modiola fornicata 18, 31, 36, 52, 55, 120
pulex 118
recta 18, 23, 27, 31, 36, 62, 120
Modiolus 73, 120
fornicatus 73, 120
rectus 73, 120
Mcerella 75, 156
salmonea 18, 36, 75, 157
Mollusca 72, 75, 76, 77, 78, 79, 80, 81, 82, S3, 84, 85, 95
MoUuscoidea 71, 92
Monia 73, 116
maoroschisma 73, 116
Monoceros 80, 246
brcvidens 247
eugouatum 19, 22, 24, 25, 28, 31, 32, 42, 55, 56
62, 80, 246, 247
var. spiratum 247
lapilloides 28, 42, 80, 246, 247
lugubre 246
punctatum 247
unicarinatum 246
Monodonta (jaUiiia 326.
Monotremata 77, 194
Mopalia 85, 343
blainvillei 343
ciliata 28, 42, 85, 343
muscosa 343
Mopaliidn) 85, 343
Motiretia reticulata 197
Murex 80, 243
adustus 243
barbarensis 254
ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO.
413
Murex belcheri 247
cali/oriiicus 243, 246
festivus 19, 24, 25, 28, 31, 244
(Pteronotus) festivus 43, 244
foliatas 28, 245
(Pterorhytis) foliatas 43, 245
foveolata 255
leeamis 25, 28, 67
(Chicoreus) leeanus 43, 243
monoceros 28, 246
(Cerostoma) monoceros 43
(Pterorhytis) mouoceros 246
multicostaius 251
uuttalli 244
(Pterorhytis) uuttalli 43, 62, 245
nux 262
ptrilus 259
tenuispina 243
trialatus 24, 25, 28, 43, 243
(Chicoreus) trialatus 243
trigonulus 244
Muricida) 80, 243
Muricidea barbarensis 254
californica 243
foveolata 255
paucivaricata 246
[Phyllonotus) paucivaricata 246
perita 259
Mya abrupta 182
cancellatus 179
glycymeris 182
norvegica 183
Myacea 179
Myacidffl 76, 179
Afysia 134
MytUacea 73, 118
Mytilidas 73, 118
Mytilimeria 73, 125
nuttalli 15, 18, 21, 37, 73, 125, 126
Mytilus 73, 118, 126
abbreviatus: 1 18
bifurcatus 119
borealis 118
californicus 50
edulis 18, 23, 25, 27, 33, 36, 49, 68, 73, 118, 119
incurvattts 118
lithophagus 121
minijanensis 118
modiolus 120
noiatus 118
pedroanus 118
pellucidus 118
smaragdiuus 118
subsaxatilis 118
vetustus 118
Myurella simplex 57, 198
Naoella depicta 317
incessa 318
inalabilis 318
Nacella paleacea 319
Narona cooperi 217
Nassa 79, 230
californiana 15, 19, 24, 28, 31, 32, 43, 55, 62,
79, 231, 232
cerritensis 25, 28, 31, 32, 43, 62, 79, 231
cooperi 17, 232, 234
fossata 15, 19, 22, 24, 25, 28, 31, 32, 33, 43, 55,
56, 62, 79, 231, 232
gibbesii 233
insculpta 28, 43, 79, 233
interstriata 234
mendica 15. 17, 19, 22, 24, 25, 28, 31, 32, 43,
52, 55, 57, 62, 80, 233, 234
var. cooperi 15, 19, 22, 24, 25, 28, 31,
32, 33, 43, 56, 62, 80, 232, 234
mutabilis 230
perpinguis 15, 17, 19, 22, 24, 25, 28, 31, 32, 43,
55, 56, 62, 80, 232, 234
pedroana 239
tegula 19, 22, 24, 25, 28, 31, 32, 43, 62, 80, 235,
236
versicolor 236
var. hooveri 28, 43, 80, 233, 236
vibex 235
woodwardi 233
NassidiB 79, 230
Natica 83, 313
algida 315
ampuUaria 315
caurena 313
clausa 15, 17, 19, 43, 52, 57, 65, 68, 313, 314
(Cryptouatica) clausa 313
duplicata 314
kwisii 24, 25, 28, 31, 315
(Lunatia) lewisii 43, 315
mammilla 314
recluiiana 314
reiniana 315
russa 313, 314
Naticidse 83, 313
Neajra 76, 181
ornatissima 181
pectiuata 18, 37, 76, 181
Neptunea tabulata 228
Neverita 83, 314
recluziana 15, 19, 22, 24, 25, 28, 31, 32, 43, 55, 56,
62, 83, 314, 315, 316
var. alt a 55
Nodipecten 72, 108
subnodosus 72, 108
Norrisia 84, 331
uorrisii 24, 43, 62, 84, 323, 331
Nucula 72, 95, 96
cmlata 98
castreusis 15, 17, 18, 21
(Acila) castrensis 37, 95
conradi 95
decisa 95
divaricata 95
414
CALIFORNIA ACADEMY OF SCIENCES.
Niicula obliqaa 96
suprastriata 18, 21, 27, 31, 30, 62, 72, !)6
(Nucula) suprastriata 96
tenuis 96
Nuculacea 72, 95
Nuculidas 72, 95
Nuttallia 76, 168
nuttalli 76, 168
Obeliscos variegata 280
Ocinebra 80, 254
barbareusis 19, 22, 43, 52, 80, 254, 259
erinaceus 254
foveolata 28, 43, 80, 255
interfossa 15, 19, 22, 24, 25, 28, 43, 62, 80, 255,
259
keepi 24, 43, 80, 256
lurida 25, 43, 62, 80, 256, 257
var. aspera 19, 22, 24, 25, 28, 31, 43, 52,
55, 80, 257
var. cancelliua 28, 43, 80, 257
var. cerritensis 19, 22, 25, 31, 43, 80, 258
var. nrnnda 19, 43, 80, 258
micheli 25, 43, 80, 259
perita 19, 24, 25, 28, 43, 52, 62, 80, 254, 255, 259
poulsoni 19, 22, 24, 25, 28, 31, 43, 62, 80, 260
Oilostomia 82, 281
{Evalea) aequisculpta 284
(Oscilla) sequiscrilpta 284
(Chrysallida) diegensis 284
(Evalea) elegaus 281
gouldii 19, 22, 43, 52, 55
(Evalea) gouldii 282
(Oscilla) grammatospira 285
jnsculpta 281
interstincta 281
(Evalea) lirata 284
nuciformis 283
var. avellana 19, 43, 52, 55, 62, 283
(Amaura) nuciformis var. avellana 283
plicata 281
(Amaura) pupiformis 283
sandvicensis 281
satura var. pupiformis 283
(Evalea) stearnsii 282
tenuis 22, 23, 28, 43, 55, 62, 82, 281
var. gouldii 282
(Ivara) terricula 285
unideutata 281
CEdalia subdiaphana 153
(Edalina subdiaphana 153
Olivella 79, 219
biplioata 15, 17, 19, 22, 24, 25, 28, 31, 32, 33, 43,
52, 55, 56, 62, 79, 219, 220, 221
bcelica 57, 221
iutorta 15, 19, 22, 24, 25, 28, 31, 32, 33, 44, 55,
56, 62, 79, 220, 221
pedroaua 15, 19, 22, 24, 25, 28, 31, 32, 44, 55,
57, 63, 79, 220, 221
uudatella 219
OlividiB 79, 219
Omphalius 84, 327
/uvescens 327
lirjulatus 327
pfeifferi 326
viridulnm var. ligulatum 84, 327, 339
Ondina 281
sulcata 281
Opalia 81, 266
anomala 58, 63, 81, 266
borealis 28, 44, 81, 266
corouata 266
creuatoides var. iusculpta 44, 81, 267
varicostata 58, 63, 81, 267
Opisthobrauchiata 77, 188
Opsichitouia 85, 343
Oscilla 82, 284
ivquisculpta 82, 284
grammatospira 82, 285
Ostracea 72, 102
Ostrea 57, 72, 102
conchaphila 49
edulis 102
lurida 18, 21, 25, 27, 31, 32, 37, 49, 56, 63, 72,
102
var. expansa 102
var. rufoides 102
maxima 103
veatchi 63
Ostreidai 72, 102
Oudardia butloni 157
Pachydesma crassatelloides 143
Pachypoma 84, 321
caelata 321
gibberosum 321
inaiquale 22, 23, 25, 28, 44, 84, 321
Paludestriua 83, 305
curta 22, 23, 28, 44, 83, 305
piscium 305
stokesi 22, 23, 28, 44, 83, 305
Pandora 73, 123
(Kennerlia) bicarinata 123
bilirala 123
(Kennerlia) filosa 124
punctata 124
Pandoridaj 73, 123
Panomya 77, 183
ampla 15, 37, 65, 77, 183
Panopea 76, 182
estrellann 182
geuerosa 15, 18, 23, 27, 31, 37, 52, 68, 76, 178, 182,
183
var. globosa 182
var. solida 182
norvegica 183
(Mya) norvegica 183
Paracyatlius 71, 88
caltha 88
humiliii 88
ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO.
415
Paraeyathus pedroensis 46, 71, 88, 89, 90
stearnsi 88, 89
Parapholas penita 184
Patella aculeata 308
anliqualus 312
inscssa 318
instabilis 318
Patelloida depicta 317
Patinopecten 72, 107
caurinus 72, 107
expausus 72, 108
Pecteii 72, 103, 107, 108, 115, 116
iequisulcatus 33, 56, 114
bellus 51, 52, 53, 72, 104, 106
(Pecteu) bellus 103
caurinus 14, 15, 17, 18, 25, 52, 58, 65, 68, 107, 108
(Patinopecten) caurinus 37, 107
circularis 114
deutatus 27, 67, 104, 105
(Pecteu) deutatus 37, 72, 104
deuticulata 27, 31
diegeusis 104, 105, 106
expansus 58, 63, 107, 108
(Patinopecten) expansus 108
floridus 106
(Hinuites) giganteus 115
hastatus 15, 18, 25, 52, 63, 109, 110, 111, 115
(Chlamys) hastatus 37, 109
hemphilli 51, 58, 63, 72, 104, 105
(Pecten) hemphilli 103, 105
hericeus 15, 18, 63, 65, 68, 109, 110, 111
(Chlamys) hericeus 37, 110
var. strategus 18, 37, 110
inca 114
intermedius 108
islaudicus 107, 109
jordani 15, 17, 18, 52
(Chlamys) jordani 37, HI
laqueatus 105
latiauritus 18, 21, 23, 25, 27, 31, 32, 33, 37, 63,
111, 112
var. fragilis 27, 31, 37
var. monotimeris 18, 21, 23, 25, 27, 31, .32,
33, 37, 55, 63
(Chlamys) latiauritus 111
var. fragilis 112
var. fucicolus 112
var. monotimeris 112
maximus 103
mesotimeris 111
monotimeris 112
newsomi 27, 31, 113
(Plagioctenium) newsomi 37, 113
nodosus 108
opuntia 52, 53, 63, HI
(Chlamys) opuntia 113
propatiilus 107
stearnsii 15, 37, 58, 63, 104, 105, 106
(Pecten) stearnsii 72, 106
subnodosus 23, 27, 108
Pecten (Nodipeoten) subnodosus 37, 108
subventricosus 63, 113
(Plagioctenium) subventricosus 114
tumidtis 114
tunica 111
ventricosus 23, 25, 27, 31, 32, 33, 55, 56, 63,
113, 114
(Plagioctenium) ventricosus 37, 114
yessoinsis 67, 107
Peotinacea 72, 103
Pectinidai 72, 103
Pectunculiuie 72, 100
Pectunculus corbis 140
patulus 131
scptenlrionalis 101
var. subobsoleta 101
Pelecypoda 15, 17, 18, 21, 23, 25, 27, 30, 33, 35, 72, 95
Penitella 77, 184
penita 77, 184
spelcea 184
Periploma 73, 121
alta 122
argentaria 23, 25, 27, 31, 37, 63, 73, 121, 122
excurva 122
iuitquivalvis 121
lenticularis 122
planinscula 122
Periplomidai 73, 121
Petricola 75, 154
arcuata 154
californica 154
carditoides 18, 23, 25, 27, 31, 33, 37, 56, 63, 75,
154, 155, 156
cognata 75, 156
(Petricolaria) cognata 37, 156
cordieri 155
cylindracea 154
denticulata 18, 27, 31, 37, 75, 155, 156
(Petricolaria) deuticulata 155
fjibha 154
(Rupellaria) lamellifera 155
lapicida 154
lithophaga 155
pedroana 155
pholadiformis 155, 156
Petricolaria 75, 155
cognata 156
denticulata 155
Petricolida) 154
Petrophila 78, 197
Phasianella 84, 321
compta 19, 22, 28, 44, 63, 84, 321
fulmoides 321
Phasianellid.-B 321
PholadidiB 156, 183
Pholadidea 77, 184
loscombiana 184
peuita 15, 23, 25, 27, 31, 37, 48, 50, 184
(Penitella) jieuita 184
Pholadiuaj 77, 183
416
CALIFORNIA ACADEMY OF SCIENCES.
Pholas concamerata 184
conradi 184
crispata 183
pcnita 184
Phorcus 84, 328
magus 328
puUigo 25, 44, 84, 328
Phyllonolus paucivaricata 246
Physa 78, 196
fontinalis 196
heterostropha 22, 23, 44, 78, 196
Physidic 78, 196
Pisania 79, 227
fortis 24, 28, 44, 56, 63, 79, 227
pusio 227
Pisces 28, 47, 85, 346
Placunanomia alope 116
cepio 116
macroschisma 56, 116
(Monia) machroschisma 116
Plagiocteujum 72, 113
newsomi 72, 113
subventricosus 72, 114
ventricosus 72, 114
PlanorbiiiEB 77, 195
Planorbis 77, 195
corueus 195
tumidus 22, 23, 28, 44, 77, 195
vermicularis 22, 23, 28, 44, 77, 195
Platyodon 76, 179
cancellatus 23, 25, 27, 31, 37, 76, 179
Pleurotoma 77, 199, 228
aurantia 206
babylonia 199
bartschi 15, 19
(Borsouia) bartschi 44, 200
cariuata 216
carpenteriana 24, 25, 28, 32, 55, 56, 63, 203
(Dolichotoma) carpenteriana 44, 202
{Surcula) carpenlerinna 202
cooperi 28
(Dolichotoma) cooperi 44, 203
dam 15, 19
(Borsonia) dalli 44, 201
gibbosa 204
hooveri 19
(Borsouia) hooveri 44, 201
hiermis 205
linearis 210
mitnL'formis 202
montereyensis 206
(Drillia) montereyensis 207
pedroana 19
(Leucosyrinx) pedroana 44, 202
penicillata 205
perversa 15, 19, 22, 24, 28, 31, 44, 56, 77, 200,
216
ponderosa 211
pudica 208
pyrenaica 200
Plenrotoma renaudi 15, 19
(Drillia) renaudi 44
smithi 15, 19
(Spirotropsis) smithi 44, 216
stromboides 211 -
tryouiana 28
(Dolichotoma) tryoniana 44, 203
{Surcula) Iryotiiana 203
turricula 209
Pleurotomidm 77, 199, 210
Pododesmus 73, 116
macroschisma 23, 25, 27, 52, 63, 68, 116, 118
(Monia) macroschisma 37, 116
rudis 116
Polyuices 83, 314
(Lunatia) lewisii 315
(Neverita) recUiziana 314
var. alta 315
Polyplacophora 85, 342
Polyphx gracilis 250
Pomaulax 84, 322
undosus 25, 28, 44, 56, 63, 84, 322
Poromyacea 73, 126
Potamis sacratum 296
Priene 82, 286
cancellatus 286
oregonensis 15, 19, 24, 25, 28, 44, 68, 82, 286
Priouodesmaeea 72, 95
Protocardia 74, 142
centifilosa 15, 17, 18, 37, 52, 74, 142
Psammobia 76, 167, 168
edentula 27, 37, 76, 168
(Psammobia) edentula 168
feroensis 167
Psammobiidas 76, 167
Psephis 75, 152
lordi 152
salmonea 18, 21, 37, 52, 76, 152
tautilla 18, 21, 23, 27, 31, 37, 75, 152, 153
Pseudoliva kellettii 230
Ptenoglossa 81, 262
Pterouotus 80, 244
Jeslivus 32, 63, 80, 244
textilis 244
Pteropsidinte 76, 177
Pterorhytis 80, 244
foliatus 80, 245
monoceros 80, 246
nuUalli 80, 245
Plychstylis caffea 327
Pulmonata 77, 194
Puucturella 85, 341
cucuUata 15, 19, 28, 44, 52, 85, 341
galeata 15, 19, 44, 85, 341
uoachiua 341
Purpura 50, 81, 260
caualiculata 50
crispata 24, 25, 28, 44, 48, 63, 68, 80, 227, 261
(Monoceros) lapilloides 247
lapillus 261
ARNOLD— THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO.
417
Purpura persica 260
saxicola 28, +4, 55, 80, 247, 261
PurpurinaB 81, 260
Pyramidella 82, 280
couica var. variegata 28, 44, 82, 280
plicata 280
Pyramidellid* 81, 269
Pyrgisculus 81, 277
lamiuata 81, 277
Pyrgiscus 81, 274
auricoma 81, 274
crebrifilata 81, 276
latifundia 81, 275
subcuspidata 81, 277
tenuicula 81, 275, 276
Pyrgolampros 81, 278
adleri 81, 280
arnoldi 82, 279
gibbosa 81, 279
lowei 81, 278
var. pedroana 81, 279
mioperplicatulus 278
Pyrgostelis 274
Pyrgostylus 272
Kaeta 76, 177
ttndulaia 18, 37, 57, 76, 174, 177
Ranella 82, 287
calif ornica 24, 25, 28, 31, 44, 63, 82, 287
mtiriciformis 248
plicata 248
spiuosa 287
triquetra 248
Hexilhcerus secta Tar. cduli.i 164
Rictaxis 77, 188
punctocalata 77, 188, 189
Rimula cucullata 341
galcata 341
Ringicardium 74, 139
procerum 74, 139
Rissoa 83, 304
acutelirata 28, 44, 55, 83, 305
costulata 304
Rissoidse 83, 304
RowMia 197
radiata 197
Rupellaria 75, 155
lamellifera 23, 37, 75, 155
Sanguinolaria 76, 168
califoriiica 161
nuttalli 27, 31, .37, 68, 168
(Nuttallia) uuttalli 168
sordida 161
SaxicavidiB 76, 182
Saxicava carditoides 154
Saxidomus 75, 151
aratus 18, 23, 25, 27, 31, 33, 37, 48, 55, 63, 75,
151
gracilis 151
nuttallii 151
(63)
Scala 81, 262
bellastriata 28, 44, 81, 26.3, 264
{Opalia) boreaUs 266
crebricostata 22, 2.3, 24, 28, 44, 55, 63, 81, 263,
265
hemphilli 28, 44, 81, 263, 264
hindsii 19, 22, 24, 28, 31, 45, 81, 263, 264, 265
indiauorum 15, 19, 22, 24, 25, 28, 31, 45, 81,
263, 264
pretiosa 262
tiucta 19, 22, 24, 25, 28, 31, 32, 45, 55, 63, 81,
263, 264, 265
Scalaria bellaslrhala 263
borealis 266
crebricostata 263
hindsii 264
indianorum 265
var. tinctn 265
stibcorotia/a 264
tincia 265
Scalidaj 81, 262
Scaphaudridas 77, 192
Scaphopoda 19, 22, 24, 25, 28, 31, 47, 77, 185
Schizopyga californiana 231
calif ornica 231
Schizothcerus nuttalli 178
scopali 75
ponderosa 75
Scrobicularia biangulata 160
Scurria mitra 318
Scutella 71, 91
excentrica 91
(Echinarachiiius) exceutricus 91
iuterliueata 16
striatula 91
Scutellidas 71, 91
Sella 82, 290
assimilata 19, 45, 82, 290
Selachii 85, 346
Semele 76, 165
decisa 21, 23, 27, 31, 38, 63, 76, 165, 166
pulchra 27, 31, 38, 63, 76, 166
var. montereyi 18, 38, 76, 166
Semelidie 75, 165
Septifer 73, 119
bifurcatus 18, 38, 119
heberti 119
lampe 73
Serpulorbis 83, 299
arenaria 299
squamigerus 19, 22, 24, 25, 28, 31, 32, 45, 63,
83, 299
(Vermicularia) 299
Sigaretus 84, 316
debilis 31, 45, 84, 316, 317
neritoideus 316
Siliqua 76, 172
calif ornica 173
lucida 18, 21, 27, 31, 38, 63, 76, 172, 173
nuttalli 173
Jane 33, I9O3.
418
CALIFORNIA ACADEMY OF SCIENCES.
Siliqua patula 76, 173
var. nuttalli 27, 38, 63, 172, 173
rndiata 172
Silequaria edentula 168
Siphonalia 79, 229
kellettii 25, 28, 31, 45, 63, 68, 79, 229
nodosa 229
Siphonium [DendropOma) lUuella 299
Solariella 84, 334
cidaris 15, 45, 67, 334
oxyhasvi 334
peiamabilis 15, 45, 67, 85, 334, 335
SoliiCurluK cali/orninnus 169
lucida 172
nutlalU 173
rndiata 172
Solen 76, 171
gibbus 169
marginatuB 171
radius 172
rosaceus 18, 21, 23, 25, 27, 38, 63, 76, 171
sicarius 15, 17, 18, 21, 23, 25, 27, 31, 38, 76, 171,
172
Tar. rosaceus 171
Solenacea 76, 171
Solemdie 76, 171, 172
Soleuoconchia 77, 185
Sphairella tumida 134
Sphcenia cnlifornka 180
Spiroglyphus 83, 299
lituella 24, 25, 28, 31, 45, 83, 299
epiroibis 299
Spirotiopsis 79, 216
smithi 79, 216
Spisula 76, 175
catilliformis 76, 176
falcata 76, 174, 176
Standella cnlifornica 174
falcata 176
naiiula 176
Stereosomala 71, 90
Strephona pedroana 221
Streptodouta 81, 262
Streptoueura 78, 198
Strioturbouilla 81, 270
alpiua 270
muricata 81, 270
similis 81, 270
steamsii 81, 271
torqnata 81, 271
var. st.yliiia SI, 272
Strongylocentrotiis 71, 90
franciscauua 20, 46, 71, 90
purpuratus 20, 46, 53, 63, 71, 90
Styliferina 82, 295
tennisculpta 19, 45, 82, 296
Stylommatophora 77, 194
Surcula carpenteriana 202
perversa 200
tryoniana 203
TaeniogloBsa 82, 285
Tagelus 76, 169
californiauus 2.3, 25, 27, 31, 32, 38, 49, 65, 75,
76, 169, 173
Tapes 75, 149, 151
diver sum 150
gracilis 151
laciuiata 27, 31, .38, 150
lineatuvi 150
litterata 149
montaua 145
staminea 18, 21, 23, 25, 27, 28, 31, 32, 33, 38,
48, 56, 63, 68, 75, 150
var. ruderata 149
tenerrima 23, 25, 27, 28, 31, 38, 55, 64, 75, 151
Tapetinaa 75, 149
Taranis 79, 215
morchii 215
strongi 15, 19, 22, 31, 45, 79, 215
Teleodesmacea 73, 127
Tellina 75, 156
al/a 160
bodegensis 18, 21, 23, 25, 27, 31, 32, 33, 38, 64,
68, 158, 159, 165
(Angulus) bodegeusis 158
buttoni 157
{Oudardia) buttoni 157
calcarea 161
donacina 156
emacerata 158
ida? 31, 38, 158, 159
(Augulus) idm 158
inquinala 162
lanceolata 157
lata 161
ligamentinn. 164
meyeri 160
(Angulus) modestus Tar. obtusus 157
nasula 163
obtusa 157
pedroana 157, 161
proxima 161
reticulata 165
rubesceus 27, 38, 159
(Augulus) rubescens 159
(Mosrella) salmouea 157
secta 164
sordidn 161
striata 158
subulosa 161
tenera 161
Telliuacea 75, 156
TellineUa 158
TelliuidiB 75, 156
Terebra 57, 78, 198
nebulosa 198
simplex 15, 17, 19, 22, 24, 25, 28, 31, 32, 64, 198
(Acus) simplex 45, 198
varicgata J 98
Terebratalia 71, 92
ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO.
419
Terebratalia hemphilli 51, 52, 5,S, 71, 92, 93
obsoleta 92
smithi 15, 46, 71, 92, 93
Terebratulida? 71, 92
Terebridae 78, 198
Thalotia 84, 327
caffea 15, 19, 45, 84, 327
conicus 327
Thuracica 85, 344
Thracia 73, 122
curta 122
pubescens 122
trapezoides 15, 17, 38, 73, 122, 123
Thraciidae 73, 122
Thyasira 74, 135
bisecta 15, 17, 38, 65, 74, 135, 136
(Cryptodou) bisecta 14
flexuosus 135
gouldi 15, 17, 38, 74, 135, 136
Thyatira bisecta 135
Tivola 74, 142
crassatelloides 18, 23, 25, 27, 31, 32, 33, 38, 64,
74, 143, 153
Tornatella 57
fasciata 188
punclocfelatn 188, 189
Tornatina 77, 189
cerealis 19, 22, 28, 45, 64, 77, 189
coarctata 189
culcitella 19, 22, 24, 25, 28, 31, 45, 52, 55, 64,
77, 190
eximia 15, 45, 77, 190
harpa 45, 55, 64, 77, 191
Tornatinidas 77, 189
Toxocidaris franciscnna 90
Toxoglossa 78, 198
Trachycardium 74, 138
quadrigeuarium 74, 139
Tresus 76, 178
maxitnufi 178
nuttalli 23, 25, 27, 31, 38, 64, 68, 76, 178, 180
TriforidiiB 82, 290
Tiiforis 82, 290
adversa 19, 45, 82, 290
perversus 290
Triyonella crassatelloides 143
Trigonia crassatelloides 143
slallorum 143
tantilla 153
Triton 287
(libbosus 28, 286
oregonense 286
(Priene) oreyovensis 286
Tritonidaj 82, 285
Tritonium 82, 285
gibbosus 45, 82, 286
luridum 256
oregonense 286
oregonensis 68
(Priene) oregonensis 286
variegatus 285
Trivia 82, 288
californica 28, 45, 82, 288, 289
qiiadripnnctata 288
solandri 45, 82, 289
Trochidie 84, 324
Trochischus convcxus 331
norrisii 331
Trochus annulatus 329
aureotinctus 324
brunneus 324
cnnaliciilalus 329
coslatus 330
funebralis 325
gaUina 326
(Monodonta) gallina 326
gibberosus 321
incequalis 321
Ugulatus 327
luridus 327
montereyi 326
pulligo 328
pupilhis 333
iDidosus 322
Trophon 65, 80, 249
cerritensis 19, 31, 250
(Boreotrophou) cerritensis 45, 249
clathratus 249
craticulatus 250
disparilis 251, 253
gracilis 15, 19, 52, 251
(Boreotroplion) gracilis 45, 250
mnlticostatus 19, 28, 250, 251, 252
(Boreotrophon) multicostatns 45, 251
orpheuB 68, 252, 253
var. prsecursor 15, 19, 45, 52, 253
pedroana 19, 22, 250, 252
(Boreotrophon) pedroana 45, 251
scalariformis 15, 19, 25, 56, 251, 252
(Boreotrophon) scalariformis 45, 252
Btiiarti 15, 17, 19, 45, 68, 250, 252, 256
(Boreotrophon) stuarti 252
tenuisculptus 15, 253
' (Boreotrophon) tenuisculptus 45, 253
triaugulatus 19, 254
(Boreotrophon) triangulatns 45, 254
Truncaria corriigala 241
Trygonid* 85, 346
TurbinidiB 84, 321
Turbinolidffi 71, 86
Turbonilla 55, 64, 81, 269, 281
adleri 19, 45
• (Pyrgolampros) adleri 280
arnoldi 19, 45
(Pyrgolampros) arnoldi 279
aspera 291
aurautia 19, 22, 28, 31, 45
(Lancea) aurantia 272
(Pyrgiscus) auricoma 274
crebrifilata 19, 22, 31, 45
(Pyrgiscus) crebritilata 276
(Lancea) ^elongata 272
420
CALIFORNIA ACADEMY OF SCIENCES.
Turbonilla gibbosa 19, 46
(Pyrgolampros) gibbosa 279
lamiuata 19, 22, 28, 31, 46, 55
(Pyrgisculus) laminata 277
latifundia 46
(Pyrgiscus) latifundia 275
lowei 19, 22, 28, 31, 46, 279
(Pyrgolampros) lowei 278
var. pedroana 279
mexicana 280
muricata 19, 22, 46
(Strioturbouilla) muricata 270
pentalopha 19, 46
(Lancea) pentalopha 274
plicaiula 269
plicatulus 269
similis 19, 22, 31, 46
(Strioturbouilla) similis 270
stearnsii 22, 23, 28, 31, 46, 270, 271
(Strioturbouilla) stearnsii 271
subcuspidata 19, 22, 28, 31, 46
(Pyrgiscus) subcuspidata 277
tenuicula 19, 22, 28, 31, 46, 276
(Pyrgiscus) tenuicula 275, 276
torquata 19, 46, 272
var. stylina 19, 22, 46, 271
(Strioturbouilla) torquata 271
var. stylina 272
tridentata 19, 22, 31, 46, .52, 273
(Lancea) trideutata 273
typica 269
Turcka (Ptychslylia) cnffra 327
Turckula chlaris 3.34
Turritella 83, 300
apicalis 300
cooperi 15, 17, 19, 22, 24, 25, 28, 31, .32, 46, 54,
55, 56, 57, 64, 83, .300, 301
jewettii 15, 19, 24, 25, 28, 46, 83, 300, 301
sanguinea .300, 301
terebra 300
Turritellid* 83, 300
Urolophus 85, 346
hallori 28, 47, 85, .346
Urosalpinx cnncellinus 257
Veneracea 74, 142
Veuericardia 74, 128
barbarensis 15, 17, 18, 25, 27, 32, ,38, 52, 74, 128
borealis 57
var. vriifricoKa 128
planicostata 128
ventricosa 15, 17, 18, 38, 52, 56, 57, 64, 128
VeueridiB 74, 142, 147
Venerinas 74, 142
Venerupis cordieri 155
Venus 75, 146
bisecla 135
brevilincata 149
californie.a 149
cnllosa 145
Venus corlizi 147
iluctifraga 27, 147
(Chione) fluctifraga 38, 147
gibbosnla 147
gnidia 27, 67, 147
(Chioue) guidia 38, 147
kenncrleyi 146
lamellifera 149, 150, 155
lapicida 154
m axima 1 5 1
neglecta 27, 31, 148
(Chione) neglecta .38, 148
nutlalli 149
perlaminosa 51, 52, 75, 146
rigida 150, 151
rysonia 153
securis 149
simillima 15, 18, 23, 25, 27, 31, 148
(Chione) simillima 38, 148
slnminra 150
succincta 23, 25, 27, 31, 149
(Chione) succincta .38, 149
tantiUus 1.53
verrucosa 146
Vermetid* 83, 299
Vermeliis squamigerun 299
Vermicularia 19, 46, 83, 299
Vertebrata 85, 346
Verticordia 73, 126
cardiiformis 126
novemcostata 18, 38, 73, 126
ornata 126
Verticordiidae 73, 126
Vitrinella 64, 85, 335
anomala 335
williamsoni 19, 28, 46, 85, 335
Vilularia axprra 257
Vola 57
denlala 104
Volvarla alba 192
Volvarina 79, 222
varia 19, 22, 24, 25, 28, 31, 4fi, 64, 79, 222
Volvula 77, 191
acuminator 191
cylindrica 19, 46, 64, 77, 191
YoLDiA 72, 99
amygdala 100
arctica 99
cooperi 27, 38, 55, 64, 72, 99, 100
impressa 99
myalis 99
scissurata 18, 38, 72, 99, 100
ZlRPnasA 77, 183
crispnla 56, 184
gabbii 2.3, 25, 27, 31, .32, 38, 56, 77, 184
Zizyphinun annulnlus 329
canaliculnlus 329
/Jto.sH.v 330
Zygobranchia 85, 336
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